diff --git a/packages/api/src/__tests__/assistant-tools-user-admin-assignable-users.test.ts b/packages/api/src/__tests__/assistant-tools-user-admin-assignable-users.test.ts
new file mode 100644
index 0000000..7f140da
--- /dev/null
+++ b/packages/api/src/__tests__/assistant-tools-user-admin-assignable-users.test.ts
@@ -0,0 +1,70 @@
+import { beforeEach, describe, expect, it, vi } from "vitest";
+import { SystemRole } from "@capakraken/shared";
+
+vi.mock("@capakraken/application", async (importOriginal) => {
+  const actual = await importOriginal<typeof import("@capakraken/application")>();
+  return {
+    ...actual,
+    getDashboardBudgetForecast: vi.fn().mockResolvedValue([]),
+    getDashboardPeakTimes: vi.fn().mockResolvedValue([]),
+    listAssignmentBookings: vi.fn().mockResolvedValue([]),
+  };
+});
+
+import { executeTool } from "../router/assistant-tools.js";
+import { createToolContext } from "./assistant-tools-user-admin-test-helpers.js";
+
+describe("assistant user admin tool list_assignable_users", () => {
+  beforeEach(() => {
+    vi.clearAllMocks();
+  });
+
+  it("lists assignable users through the real user router path for manager users", async () => {
+    const findMany = vi.fn().mockResolvedValue([
+      { id: "user_1", name: "Alice", email: "alice@example.com" },
+    ]);
+    const ctx = createToolContext({
+      user: {
+        findMany,
+      },
+    }, SystemRole.MANAGER);
+
+    const result = await executeTool(
+      "list_assignable_users",
+      JSON.stringify({}),
+      ctx,
+    );
+
+    expect(JSON.parse(result.content)).toEqual([
+      { id: "user_1", name: "Alice", email: "alice@example.com" },
+    ]);
+    expect(findMany).toHaveBeenCalledWith({
+      select: {
+        id: true,
+        name: true,
+        email: true,
+      },
+      orderBy: { name: "asc" },
+    });
+  });
+
+  it("rejects assignable user listing for regular users through the backing router", async () => {
+    const ctx = createToolContext({
+      user: {
+        findMany: vi.fn(),
+      },
+    }, SystemRole.USER);
+
+    const result = await executeTool(
+      "list_assignable_users",
+      JSON.stringify({}),
+      ctx,
+    );
+
+    expect(JSON.parse(result.content)).toEqual(
+      expect.objectContaining({
+        error: "You do not have permission to perform this action.",
+      }),
+    );
+  });
+});
diff --git a/packages/api/src/__tests__/assistant-tools-user-admin-inventory-read.test.ts b/packages/api/src/__tests__/assistant-tools-user-admin-inventory-read.test.ts
new file mode 100644
index 0000000..a094e47
--- /dev/null
+++ b/packages/api/src/__tests__/assistant-tools-user-admin-inventory-read.test.ts
@@ -0,0 +1,88 @@
+import { beforeEach, describe, expect, it, vi } from "vitest";
+import { SystemRole } from "@capakraken/shared";
+
+vi.mock("@capakraken/application", async (importOriginal) => {
+  const actual = await importOriginal<typeof import("@capakraken/application")>();
+  return {
+    ...actual,
+    getDashboardBudgetForecast: vi.fn().mockResolvedValue([]),
+    getDashboardPeakTimes: vi.fn().mockResolvedValue([]),
+    listAssignmentBookings: vi.fn().mockResolvedValue([]),
+  };
+});
+
+import { executeTool } from "../router/assistant-tools.js";
+import { createToolContext } from "./assistant-tools-user-admin-test-helpers.js";
+
+describe("assistant user admin inventory read tools", () => {
+  beforeEach(() => {
+    vi.clearAllMocks();
+  });
+
+  it("returns the active user count for admin users", async () => {
+    const count = vi.fn().mockResolvedValue(4);
+    const ctx = createToolContext({
+      user: {
+        count,
+      },
+    }, SystemRole.ADMIN);
+
+    const result = await executeTool(
+      "get_active_user_count",
+      JSON.stringify({}),
+      ctx,
+    );
+
+    expect(JSON.parse(result.content)).toEqual({ count: 4 });
+    expect(count).toHaveBeenCalledWith({
+      where: {
+        lastActiveAt: {
+          gte: expect.any(Date),
+        },
+      },
+    });
+  });
+
+  it("lists users only for admins through the real user router", async () => {
+    const db = {
+      user: {
+        findMany: vi.fn().mockResolvedValue([
+          { id: "user_1", name: "Alice", email: "alice@example.com" },
+          { id: "user_2", name: "Bob", email: "bob@example.com" },
+        ]),
+      },
+    };
+    const adminCtx = createToolContext(db, SystemRole.ADMIN);
+    const managerCtx = createToolContext({}, SystemRole.MANAGER);
+
+    const adminResult = await executeTool(
+      "list_users",
+      JSON.stringify({ limit: 1 }),
+      adminCtx,
+    );
+    const deniedResult = await executeTool("list_users", "{}", managerCtx);
+
+    expect(db.user.findMany).toHaveBeenCalledWith({
+      select: {
+        id: true,
+        name: true,
+        email: true,
+        systemRole: true,
+        createdAt: true,
+        lastLoginAt: true,
+        lastActiveAt: true,
+        permissionOverrides: true,
+        totpEnabled: true,
+      },
+      orderBy: { name: "asc" },
+    });
+    expect(JSON.parse(adminResult.content)).toEqual([
+      expect.objectContaining({ id: "user_1", name: "Alice" }),
+    ]);
+    expect(JSON.parse(deniedResult.content)).toEqual(
+      expect.objectContaining({
+        error: "You do not have permission to perform this action.",
+      }),
+    );
+  });
+});
diff --git a/packages/api/src/__tests__/assistant-tools-user-admin-name-errors.test.ts b/packages/api/src/__tests__/assistant-tools-user-admin-name-errors.test.ts
new file mode 100644
index 0000000..fa901c5
--- /dev/null
+++ b/packages/api/src/__tests__/assistant-tools-user-admin-name-errors.test.ts
@@ -0,0 +1,86 @@
+import { beforeEach, describe, expect, it, vi } from "vitest";
+import { SystemRole } from "@capakraken/shared";
+
+vi.mock("@capakraken/application", async (importOriginal) => {
+  const actual = await importOriginal<typeof import("@capakraken/application")>();
+  return {
+    ...actual,
+    getDashboardBudgetForecast: vi.fn().mockResolvedValue([]),
+    getDashboardPeakTimes: vi.fn().mockResolvedValue([]),
+    listAssignmentBookings: vi.fn().mockResolvedValue([]),
+  };
+});
+
+import { executeTool } from "../router/assistant-tools.js";
+import { createToolContext } from "./assistant-tools-user-admin-test-helpers.js";
+
+describe("assistant user admin name update errors", () => {
+  beforeEach(() => {
+    vi.clearAllMocks();
+  });
+
+  it("returns a stable error when renaming a missing user", async () => {
+    const ctx = createToolContext(
+      {
+        user: {
+          findUnique: vi.fn().mockResolvedValue(null),
+        },
+      },
+      SystemRole.ADMIN,
+    );
+
+    const result = await executeTool(
+      "update_user_name",
+      JSON.stringify({ id: "user_missing", name: "Miles Morales" }),
+      ctx,
+    );
+
+    expect(JSON.parse(result.content)).toEqual(expect.objectContaining({
+      error: "User not found with the given criteria.",
+    }));
+  });
+
+  it("returns a stable error when renaming a user without a name", async () => {
+    const ctx = createToolContext(
+      {
+        user: {
+          findUnique: vi.fn(),
+        },
+      },
+      SystemRole.ADMIN,
+    );
+
+    const result = await executeTool(
+      "update_user_name",
+      JSON.stringify({ id: "user_1", name: "" }),
+      ctx,
+    );
+
+    expect(JSON.parse(result.content)).toEqual(expect.objectContaining({
+      error: "Name is required.",
+    }));
+    expect(ctx.db.user.findUnique).not.toHaveBeenCalled();
+  });
+
+  it("returns a stable error when renaming a user with a name that is too long", async () => {
+    const ctx = createToolContext(
+      {
+        user: {
+          findUnique: vi.fn(),
+        },
+      },
+      SystemRole.ADMIN,
+    );
+
+    const result = await executeTool(
+      "update_user_name",
+      JSON.stringify({ id: "user_1", name: "x".repeat(201) }),
+      ctx,
+    );
+
+    expect(JSON.parse(result.content)).toEqual(expect.objectContaining({
+      error: "Name must be at most 200 characters.",
+    }));
+    expect(ctx.db.user.findUnique).not.toHaveBeenCalled();
+  });
+});
diff --git a/packages/api/src/__tests__/assistant-tools-user-admin-password-role-errors.test.ts b/packages/api/src/__tests__/assistant-tools-user-admin-password-role-errors.test.ts
new file mode 100644
index 0000000..2f7040a
--- /dev/null
+++ b/packages/api/src/__tests__/assistant-tools-user-admin-password-role-errors.test.ts
@@ -0,0 +1,85 @@
+import { beforeEach, describe, expect, it, vi } from "vitest";
+import { SystemRole } from "@capakraken/shared";
+
+vi.mock("@capakraken/application", async (importOriginal) => {
+  const actual = await importOriginal<typeof import("@capakraken/application")>();
+  return {
+    ...actual,
+    getDashboardBudgetForecast: vi.fn().mockResolvedValue([]),
+    getDashboardPeakTimes: vi.fn().mockResolvedValue([]),
+    listAssignmentBookings: vi.fn().mockResolvedValue([]),
+  };
+});
+
+import { executeTool } from "../router/assistant-tools.js";
+import { createToolContext } from "./assistant-tools-user-admin-test-helpers.js";
+
+describe("assistant user admin password and role errors", () => {
+  beforeEach(() => {
+    vi.clearAllMocks();
+  });
+
+  it("returns a stable error when resetting the password of a missing user", async () => {
+    const ctx = createToolContext(
+      {
+        user: {
+          findUnique: vi.fn().mockResolvedValue(null),
+        },
+      },
+      SystemRole.ADMIN,
+    );
+
+    const result = await executeTool(
+      "set_user_password",
+      JSON.stringify({ userId: "user_missing", password: "secret123" }),
+      ctx,
+    );
+
+    expect(JSON.parse(result.content)).toEqual(expect.objectContaining({
+      error: "User not found with the given criteria.",
+    }));
+  });
+
+  it("returns a stable error when resetting a password that is too short", async () => {
+    const ctx = createToolContext(
+      {
+        user: {
+          findUnique: vi.fn(),
+        },
+      },
+      SystemRole.ADMIN,
+    );
+
+    const result = await executeTool(
+      "set_user_password",
+      JSON.stringify({ userId: "user_1", password: "short" }),
+      ctx,
+    );
+
+    expect(JSON.parse(result.content)).toEqual(expect.objectContaining({
+      error: "Password must be at least 8 characters.",
+    }));
+    expect(ctx.db.user.findUnique).not.toHaveBeenCalled();
+  });
+
+  it("returns a stable error when updating the role of a missing user", async () => {
+    const ctx = createToolContext(
+      {
+        user: {
+          findUnique: vi.fn().mockResolvedValue(null),
+        },
+      },
+      SystemRole.ADMIN,
+    );
+
+    const result = await executeTool(
+      "update_user_role",
+      JSON.stringify({ id: "user_missing", systemRole: SystemRole.MANAGER }),
+      ctx,
+    );
+
+    expect(JSON.parse(result.content)).toEqual(expect.objectContaining({
+      error: "User not found with the given criteria.",
+    }));
+  });
+});
diff --git a/packages/api/src/__tests__/assistant-tools-user-admin-resource-auto-linking.test.ts b/packages/api/src/__tests__/assistant-tools-user-admin-resource-auto-linking.test.ts
new file mode 100644
index 0000000..b9c7c1a
--- /dev/null
+++ b/packages/api/src/__tests__/assistant-tools-user-admin-resource-auto-linking.test.ts
@@ -0,0 +1,71 @@
+import { beforeEach, describe, expect, it, vi } from "vitest";
+import { SystemRole } from "@capakraken/shared";
+
+vi.mock("@capakraken/application", async (importOriginal) => {
+  const actual = await importOriginal<typeof import("@capakraken/application")>();
+  return {
+    ...actual,
+    getDashboardBudgetForecast: vi.fn().mockResolvedValue([]),
+    getDashboardPeakTimes: vi.fn().mockResolvedValue([]),
+    listAssignmentBookings: vi.fn().mockResolvedValue([]),
+  };
+});
+
+import { executeTool } from "../router/assistant-tools.js";
+import { createToolContext } from "./assistant-tools-user-admin-test-helpers.js";
+
+describe("assistant user admin tools resource linking", () => {
+  beforeEach(() => {
+    vi.clearAllMocks();
+  });
+
+  it("auto-links users by email for admin users and returns an invalidation action", async () => {
+    const findMany = vi.fn().mockResolvedValue([
+      { id: "user_1", email: "alice@example.com" },
+      { id: "user_2", email: "bob@example.com" },
+    ]);
+    const findFirst = vi.fn().mockResolvedValueOnce({ id: "resource_1" }).mockResolvedValueOnce(null);
+    const update = vi.fn().mockResolvedValue(undefined);
+    const ctx = createToolContext(
+      {
+        user: {
+          findMany,
+        },
+        resource: {
+          findFirst,
+          update,
+        },
+      },
+      SystemRole.ADMIN,
+    );
+
+    const result = await executeTool("auto_link_users_by_email", JSON.stringify({}), ctx);
+
+    expect(result.action).toEqual({
+      type: "invalidate",
+      scope: ["user", "resource"],
+    });
+    expect(result.data).toMatchObject({
+      success: true,
+      linked: 1,
+      checked: 2,
+      message: "Auto-linked 1 user(s) by email.",
+    });
+    expect(findMany).toHaveBeenCalledWith({
+      where: { resource: null },
+      select: { id: true, email: true },
+    });
+    expect(findFirst).toHaveBeenNthCalledWith(1, {
+      where: { email: "alice@example.com", userId: null },
+      select: { id: true },
+    });
+    expect(findFirst).toHaveBeenNthCalledWith(2, {
+      where: { email: "bob@example.com", userId: null },
+      select: { id: true },
+    });
+    expect(update).toHaveBeenCalledWith({
+      where: { id: "resource_1" },
+      data: { userId: "user_1" },
+    });
+  });
+});
diff --git a/packages/api/src/__tests__/assistant-tools-user-admin-resource-linking-conflict-errors.test.ts b/packages/api/src/__tests__/assistant-tools-user-admin-resource-linking-conflict-errors.test.ts
new file mode 100644
index 0000000..bb1138d
--- /dev/null
+++ b/packages/api/src/__tests__/assistant-tools-user-admin-resource-linking-conflict-errors.test.ts
@@ -0,0 +1,71 @@
+import { beforeEach, describe, expect, it, vi } from "vitest";
+import { SystemRole } from "@capakraken/shared";
+
+vi.mock("@capakraken/application", async (importOriginal) => {
+  const actual = await importOriginal<typeof import("@capakraken/application")>();
+  return {
+    ...actual,
+    getDashboardBudgetForecast: vi.fn().mockResolvedValue([]),
+    getDashboardPeakTimes: vi.fn().mockResolvedValue([]),
+    listAssignmentBookings: vi.fn().mockResolvedValue([]),
+  };
+});
+
+import { executeTool } from "../router/assistant-tools.js";
+import { createToolContext } from "./assistant-tools-user-admin-test-helpers.js";
+
+describe("assistant user admin resource linking conflict errors", () => {
+  beforeEach(() => {
+    vi.clearAllMocks();
+  });
+
+  it("returns a stable error when linking a resource that is already linked to another user", async () => {
+    const ctx = createToolContext(
+      {
+        user: {
+          findUnique: vi.fn().mockResolvedValue({ id: "user_1" }),
+        },
+        resource: {
+          findUnique: vi.fn().mockResolvedValue({ id: "resource_1", userId: "user_2" }),
+          updateMany: vi.fn(),
+        },
+      },
+      SystemRole.ADMIN,
+    );
+
+    const result = await executeTool(
+      "link_user_resource",
+      JSON.stringify({ userId: "user_1", resourceId: "resource_1" }),
+      ctx,
+    );
+
+    expect(JSON.parse(result.content)).toEqual({
+      error: "Resource is already linked to another user.",
+    });
+  });
+
+  it("returns a stable retry error when the resource link changes during update", async () => {
+    const ctx = createToolContext(
+      {
+        user: {
+          findUnique: vi.fn().mockResolvedValue({ id: "user_1" }),
+        },
+        resource: {
+          findUnique: vi.fn().mockResolvedValue({ id: "resource_1", userId: null }),
+          updateMany: vi.fn().mockResolvedValueOnce({ count: 0 }).mockResolvedValueOnce({ count: 0 }),
+        },
+      },
+      SystemRole.ADMIN,
+    );
+
+    const result = await executeTool(
+      "link_user_resource",
+      JSON.stringify({ userId: "user_1", resourceId: "resource_1" }),
+      ctx,
+    );
+
+    expect(JSON.parse(result.content)).toEqual({
+      error: "Resource link changed during update. Please retry.",
+    });
+  });
+});
diff --git a/packages/api/src/__tests__/assistant-tools-user-admin-resource-linking-not-found-errors.test.ts b/packages/api/src/__tests__/assistant-tools-user-admin-resource-linking-not-found-errors.test.ts
new file mode 100644
index 0000000..9ce6c93
--- /dev/null
+++ b/packages/api/src/__tests__/assistant-tools-user-admin-resource-linking-not-found-errors.test.ts
@@ -0,0 +1,147 @@
+import { beforeEach, describe, expect, it, vi } from "vitest";
+import { SystemRole } from "@capakraken/shared";
+
+vi.mock("@capakraken/application", async (importOriginal) => {
+  const actual = await importOriginal<typeof import("@capakraken/application")>();
+  return {
+    ...actual,
+    getDashboardBudgetForecast: vi.fn().mockResolvedValue([]),
+    getDashboardPeakTimes: vi.fn().mockResolvedValue([]),
+    listAssignmentBookings: vi.fn().mockResolvedValue([]),
+  };
+});
+
+import { executeTool } from "../router/assistant-tools.js";
+import { createToolContext } from "./assistant-tools-user-admin-test-helpers.js";
+
+describe("assistant user admin resource linking not-found errors", () => {
+  beforeEach(() => {
+    vi.clearAllMocks();
+  });
+
+  it("returns a stable error when linking a missing user to a resource", async () => {
+    const ctx = createToolContext(
+      {
+        user: {
+          findUnique: vi.fn().mockResolvedValue(null),
+        },
+      },
+      SystemRole.ADMIN,
+    );
+
+    const result = await executeTool(
+      "link_user_resource",
+      JSON.stringify({ userId: "user_missing", resourceId: "res_1" }),
+      ctx,
+    );
+
+    expect(JSON.parse(result.content)).toEqual({
+      error: "User not found with the given criteria.",
+    });
+  });
+
+  it("returns a stable error when linking a user to a missing resource", async () => {
+    const ctx = createToolContext(
+      {
+        user: {
+          findUnique: vi.fn().mockResolvedValue({ id: "user_1" }),
+        },
+        resource: {
+          findUnique: vi.fn().mockResolvedValue(null),
+        },
+      },
+      SystemRole.ADMIN,
+    );
+
+    const result = await executeTool(
+      "link_user_resource",
+      JSON.stringify({ userId: "user_1", resourceId: "res_missing" }),
+      ctx,
+    );
+
+    expect(JSON.parse(result.content)).toEqual({
+      error: "Resource not found with the given criteria.",
+    });
+  });
+
+  it("returns a stable error when linking a user to a resource that disappears during persistence", async () => {
+    const ctx = createToolContext(
+      {
+        user: {
+          findUnique: vi.fn().mockResolvedValue({ id: "user_1" }),
+        },
+        resource: {
+          findUnique: vi.fn().mockResolvedValueOnce({ id: "res_1", userId: null }).mockResolvedValueOnce(null),
+          updateMany: vi.fn().mockResolvedValueOnce({ count: 0 }).mockResolvedValueOnce({ count: 0 }),
+        },
+      },
+      SystemRole.ADMIN,
+    );
+
+    const result = await executeTool(
+      "link_user_resource",
+      JSON.stringify({ userId: "user_1", resourceId: "res_1" }),
+      ctx,
+    );
+
+    expect(JSON.parse(result.content)).toEqual({
+      error: "Resource not found with the given criteria.",
+    });
+  });
+
+  it("returns a stable error when linking a user after the user disappears during persistence", async () => {
+    const ctx = createToolContext(
+      {
+        user: {
+          findUnique: vi.fn().mockResolvedValueOnce({ id: "user_1" }).mockResolvedValueOnce(null),
+        },
+        resource: {
+          findUnique: vi
+            .fn()
+            .mockResolvedValueOnce({ id: "res_1", userId: null })
+            .mockResolvedValueOnce({ id: "res_1", userId: null }),
+          updateMany: vi.fn().mockResolvedValueOnce({ count: 0 }).mockResolvedValueOnce({ count: 0 }),
+        },
+      },
+      SystemRole.ADMIN,
+    );
+
+    const result = await executeTool(
+      "link_user_resource",
+      JSON.stringify({ userId: "user_1", resourceId: "res_1" }),
+      ctx,
+    );
+
+    expect(JSON.parse(result.content)).toEqual({
+      error: "User not found with the given criteria.",
+    });
+  });
+
+  it("returns a stable error when linking a user after the user disappears and prisma reports an array target", async () => {
+    const ctx = createToolContext(
+      {
+        user: {
+          findUnique: vi.fn().mockResolvedValueOnce({ id: "user_1" }).mockResolvedValueOnce(null),
+        },
+        resource: {
+          findUnique: vi
+            .fn()
+            .mockResolvedValueOnce({ id: "res_1", userId: null })
+            .mockResolvedValueOnce({ id: "res_1", userId: null }),
+          updateMany: vi.fn().mockResolvedValueOnce({ count: 0 }).mockResolvedValueOnce({ count: 0 }),
+        },
+      },
+      SystemRole.ADMIN,
+    );
+
+    const result = await executeTool(
+      "link_user_resource",
+      JSON.stringify({ userId: "user_1", resourceId: "res_1" }),
+      ctx,
+    );
+
+    expect(JSON.parse(result.content)).toEqual({
+      error: "User not found with the given criteria.",
+    });
+  });
+});
diff --git a/packages/api/src/__tests__/assistant-tools-user-admin-resource-linking-success.test.ts b/packages/api/src/__tests__/assistant-tools-user-admin-resource-linking-success.test.ts
new file mode 100644
index 0000000..8d6e910
--- /dev/null
+++ b/packages/api/src/__tests__/assistant-tools-user-admin-resource-linking-success.test.ts
@@ -0,0 +1,116 @@
+import { beforeEach, describe, expect, it, vi } from "vitest";
+import { SystemRole } from "@capakraken/shared";
+
+vi.mock("@capakraken/application", async (importOriginal) => {
+  const actual = await importOriginal<typeof import("@capakraken/application")>();
+  return {
+    ...actual,
+    getDashboardBudgetForecast: vi.fn().mockResolvedValue([]),
+    getDashboardPeakTimes: vi.fn().mockResolvedValue([]),
+    listAssignmentBookings: vi.fn().mockResolvedValue([]),
+  };
+});
+
+import { executeTool } from "../router/assistant-tools.js";
+import { createToolContext } from "./assistant-tools-user-admin-test-helpers.js";
+
+describe("assistant user admin tools resource linking", () => {
+  beforeEach(() => {
+    vi.clearAllMocks();
+  });
+
+  it("links a user to a resource for admin users and returns an invalidation action", async () => {
+    const userFindUnique = vi.fn().mockResolvedValue({ id: "user_1" });
+    const resourceFindUnique = vi.fn().mockResolvedValue({ id: "resource_1", userId: null });
+    const updateMany = vi.fn().mockResolvedValueOnce({ count: 1 }).mockResolvedValueOnce({ count: 1 });
+    const ctx = createToolContext(
+      {
+        user: {
+          findUnique: userFindUnique,
+        },
+        resource: {
+          findUnique: resourceFindUnique,
+          updateMany,
+        },
+      },
+      SystemRole.ADMIN,
+    );
+
+    const result = await executeTool(
+      "link_user_resource",
+      JSON.stringify({ userId: "user_1", resourceId: "resource_1" }),
+      ctx,
+    );
+
+    expect(result.action).toEqual({
+      type: "invalidate",
+      scope: ["user", "resource"],
+    });
+    expect(result.data).toEqual({
+      success: true,
+      message: "Linked user to resource.",
+    });
+    expect(userFindUnique).toHaveBeenCalledWith({
+      where: { id: "user_1" },
+      select: { id: true },
+    });
+    expect(resourceFindUnique).toHaveBeenCalledWith({
+      where: { id: "resource_1" },
+      select: { id: true, userId: true },
+    });
+    expect(updateMany).toHaveBeenNthCalledWith(1, {
+      where: {
+        userId: "user_1",
+        NOT: { id: "resource_1" },
+      },
+      data: { userId: null },
+    });
+    expect(updateMany).toHaveBeenNthCalledWith(2, {
+      where: {
+        id: "resource_1",
+        OR: [{ userId: null }, { userId: "user_1" }],
+      },
+      data: { userId: "user_1" },
+    });
+  });
+
+  it("unlinks a user resource for admin users and returns an invalidation action", async () => {
+    const userFindUnique = vi.fn().mockResolvedValue({ id: "user_1" });
+    const updateMany = vi.fn().mockResolvedValue({ count: 1 });
+    const ctx = createToolContext(
+      {
+        user: {
+          findUnique: userFindUnique,
+        },
+        resource: {
+          findUnique: vi.fn(),
+          updateMany,
+        },
+      },
+      SystemRole.ADMIN,
+    );
+
+    const result = await executeTool(
+      "link_user_resource",
+      JSON.stringify({ userId: "user_1", resourceId: null }),
+      ctx,
+    );
+
+    expect(result.action).toEqual({
+      type: "invalidate",
+      scope: ["user", "resource"],
+    });
+    expect(result.data).toEqual({
+      success: true,
+      message: "Unlinked user resource.",
+    });
+    expect(userFindUnique).toHaveBeenCalledWith({
+      where: { id: "user_1" },
+      select: { id: true },
+    });
+    expect(updateMany).toHaveBeenCalledWith({
+      where: { userId: "user_1" },
+      data: { userId: null },
+    });
+  });
+});
diff --git a/packages/api/src/__tests__/assistant-tools-user-admin-test-helpers.ts b/packages/api/src/__tests__/assistant-tools-user-admin-test-helpers.ts
new file mode 100644
index 0000000..88eaae4
--- /dev/null
+++ b/packages/api/src/__tests__/assistant-tools-user-admin-test-helpers.ts
@@ -0,0 +1,25 @@
+import { SystemRole } from "@capakraken/shared";
+
+import type { ToolContext } from "../router/assistant-tools.js";
+
+export function createToolContext(
+  db: Record<string, unknown>,
+  userRole: SystemRole,
+): ToolContext {
+  return {
+    db: db as ToolContext["db"],
+    userId: "user_1",
+    userRole,
+    permissions: new Set(),
+    session: {
+      user: { email: "user@example.com", name: "Assistant User", image: null },
+      expires: "2026-03-29T00:00:00.000Z",
+    },
+    dbUser: {
+      id: "user_1",
+      systemRole: userRole,
+      permissionOverrides: null,
+    },
+    roleDefaults: null,
+  };
+}
diff --git a/packages/api/src/__tests__/assistant-tools-user-admin-user-create-errors.test.ts b/packages/api/src/__tests__/assistant-tools-user-admin-user-create-errors.test.ts
new file mode 100644
index 0000000..a1badf8
--- /dev/null
+++ b/packages/api/src/__tests__/assistant-tools-user-admin-user-create-errors.test.ts
@@ -0,0 +1,102 @@
+import { beforeEach, describe, expect, it, vi } from "vitest";
+import { SystemRole } from "@capakraken/shared";
+
+vi.mock("@capakraken/application", async (importOriginal) => {
+  const actual = await importOriginal<typeof import("@capakraken/application")>();
+  return {
+    ...actual,
+    getDashboardBudgetForecast: vi.fn().mockResolvedValue([]),
+    getDashboardPeakTimes: vi.fn().mockResolvedValue([]),
+    listAssignmentBookings: vi.fn().mockResolvedValue([]),
+  };
+});
+
+import { executeTool } from "../router/assistant-tools.js";
+import { createToolContext } from "./assistant-tools-user-admin-test-helpers.js";
+
+describe("assistant user admin tools user create errors", () => {
+  beforeEach(() => {
+    vi.clearAllMocks();
+  });
+
+  it("returns a stable error when creating a user with a duplicate email", async () => {
+    const ctx = createToolContext(
+      {
+        user: {
+          findUnique: vi.fn().mockResolvedValue({
+            id: "user_existing",
+            email: "peter.parker@example.com",
+            name: "Peter Parker",
+          }),
+        },
+      },
+      SystemRole.ADMIN,
+    );
+
+    const result = await executeTool(
+      "create_user",
+      JSON.stringify({
+        email: "peter.parker@example.com",
+        name: "Peter Parker",
+        password: "secret123",
+      }),
+      ctx,
+    );
+
+    expect(JSON.parse(result.content)).toEqual(expect.objectContaining({
+      error: "User with this email already exists.",
+    }));
+  });
+
+  it("returns a stable error when creating a user without a name", async () => {
+    const ctx = createToolContext(
+      {
+        user: {
+          findUnique: vi.fn(),
+        },
+      },
+      SystemRole.ADMIN,
+    );
+
+    const result = await executeTool(
+      "create_user",
+      JSON.stringify({
+        email: "miles.morales@example.com",
+        name: "",
+        password: "secret123",
+      }),
+      ctx,
+    );
+
+    expect(JSON.parse(result.content)).toEqual(expect.objectContaining({
+      error: "Name is required.",
+    }));
+    expect(ctx.db.user.findUnique).not.toHaveBeenCalled();
+  });
+
+  it("returns a stable error when creating a user with a password that is too short", async () => {
+    const ctx = createToolContext(
+      {
+        user: {
+          findUnique: vi.fn(),
+        },
+      },
+      SystemRole.ADMIN,
+    );
+
+    const result = await executeTool(
+      "create_user",
+      JSON.stringify({
+        email: "miles.morales@example.com",
+        name: "Miles Morales",
+        password: "short",
+      }),
+      ctx,
+    );
+
+    expect(JSON.parse(result.content)).toEqual(expect.objectContaining({
+      error: "Password must be at least 8 characters.",
+    }));
+    expect(ctx.db.user.findUnique).not.toHaveBeenCalled();
+  });
+});
diff --git a/packages/api/src/__tests__/assistant-tools-user-admin-user-permissions-totp.test.ts b/packages/api/src/__tests__/assistant-tools-user-admin-user-permissions-totp.test.ts
new file mode 100644
index 0000000..b638a5c
--- /dev/null
+++ b/packages/api/src/__tests__/assistant-tools-user-admin-user-permissions-totp.test.ts
@@ -0,0 +1,105 @@
+import { beforeEach, describe, expect, it, vi } from "vitest";
+import { SystemRole } from "@capakraken/shared";
+
+vi.mock("@capakraken/application", async (importOriginal) => {
+  const actual = await importOriginal<typeof import("@capakraken/application")>();
+  return {
+    ...actual,
+    getDashboardBudgetForecast: vi.fn().mockResolvedValue([]),
+    getDashboardPeakTimes: vi.fn().mockResolvedValue([]),
+    listAssignmentBookings: vi.fn().mockResolvedValue([]),
+  };
+});
+
+import { executeTool } from "../router/assistant-tools.js";
+import { createToolContext } from "./assistant-tools-user-admin-test-helpers.js";
+
+describe("assistant user admin tools permissions and totp errors", () => {
+  beforeEach(() => {
+    vi.clearAllMocks();
+  });
+
+  it("returns a stable error when setting permissions for a missing user", async () => {
+    const ctx = createToolContext(
+      {
+        user: {
+          findUnique: vi.fn().mockResolvedValue(null),
+        },
+      },
+      SystemRole.ADMIN,
+    );
+
+    const result = await executeTool(
+      "set_user_permissions",
+      JSON.stringify({ userId: "user_missing", overrides: { granted: ["manageProjects"] } }),
+      ctx,
+    );
+
+    expect(JSON.parse(result.content)).toEqual(expect.objectContaining({
+      error: "User not found with the given criteria.",
+    }));
+  });
+
+  it("returns a stable error when resetting permissions for a missing user", async () => {
+    const ctx = createToolContext(
+      {
+        user: {
+          findUnique: vi.fn().mockResolvedValue(null),
+        },
+      },
+      SystemRole.ADMIN,
+    );
+
+    const result = await executeTool(
+      "reset_user_permissions",
+      JSON.stringify({ userId: "user_missing" }),
+      ctx,
+    );
+
+    expect(JSON.parse(result.content)).toEqual(expect.objectContaining({
+      error: "User not found with the given criteria.",
+    }));
+  });
+
+  it("returns a stable error when reading effective permissions for a missing user", async () => {
+    const ctx = createToolContext(
+      {
+        user: {
+          findUnique: vi.fn().mockResolvedValue(null),
+        },
+      },
+      SystemRole.ADMIN,
+    );
+
+    const result = await executeTool(
+      "get_effective_user_permissions",
+      JSON.stringify({ userId: "user_missing" }),
+      ctx,
+    );
+
+    expect(JSON.parse(result.content)).toEqual(expect.objectContaining({
+      error: "User not found with the given criteria.",
+    }));
+  });
+
+  it("returns a stable error when disabling TOTP for a missing user", async () => {
+    const ctx = createToolContext(
+      {
+        user: {
+          findUnique: vi.fn().mockResolvedValue(null),
+        },
+      },
+      SystemRole.ADMIN,
+    );
+
+    const result = await executeTool(
+      "disable_user_totp",
+      JSON.stringify({ userId: "user_missing" }),
+      ctx,
+    );
+
+    expect(JSON.parse(result.content)).toEqual(expect.objectContaining({
+      error: "User not found with the given criteria.",
+    }));
+  });
+});
diff --git a/packages/api/src/__tests__/assistant-tools-user-self-service-auth-guard.test.ts b/packages/api/src/__tests__/assistant-tools-user-self-service-auth-guard.test.ts
new file mode 100644
index 0000000..86b7a32
--- /dev/null
+++ b/packages/api/src/__tests__/assistant-tools-user-self-service-auth-guard.test.ts
@@ -0,0 +1,59 @@
+import { beforeEach, describe, expect, it, vi } from "vitest";
+import { SystemRole } from "@capakraken/shared";
+
+vi.mock("@capakraken/application", async (importOriginal) => {
+  const actual = await importOriginal<typeof import("@capakraken/application")>();
+  return {
+    ...actual,
+    getDashboardBudgetForecast: vi.fn().mockResolvedValue([]),
+    getDashboardPeakTimes: vi.fn().mockResolvedValue([]),
+    listAssignmentBookings: vi.fn().mockResolvedValue([]),
+  };
+});
+
+import { executeTool, type ToolContext } from "../router/assistant-tools.js";
+import { createToolContext } from "./assistant-tools-user-self-service-test-helpers.js";
+
+describe("assistant user self-service auth guard tools", () => {
+  beforeEach(() => {
+    vi.clearAllMocks();
+  });
+
+  it("returns a stable assistant error when authenticated assistant context is missing for a self-service read tool", async () => {
+    const ctx = {
+      ...createToolContext({}, SystemRole.ADMIN),
+      session: null,
+      dbUser: null,
+    } as unknown as ToolContext;
+
+    const result = await executeTool("get_current_user", "{}", ctx);
+
+    expect(JSON.parse(result.content)).toEqual({
+      error: "Authenticated assistant context is required for this tool.",
+    });
+  });
+
+  it("returns a stable assistant error when authenticated assistant context is missing for a self-service mutation tool", async () => {
+    const ctx = {
+      ...createToolContext({}, SystemRole.ADMIN),
+      session: null,
+      dbUser: null,
+    } as unknown as ToolContext;
+
+    const result = await executeTool(
+      "save_dashboard_layout",
+      JSON.stringify({
+        layout: {
+          version: 2,
+          gridCols: 12,
+          widgets: [],
+        },
+      }),
+      ctx,
+    );
+
+    expect(JSON.parse(result.content)).toEqual({
+      error: "Authenticated assistant context is required for this tool.",
+    });
+  });
+});
diff --git a/packages/api/src/__tests__/assistant-tools-user-self-service-column-preferences.test.ts b/packages/api/src/__tests__/assistant-tools-user-self-service-column-preferences.test.ts
new file mode 100644
index 0000000..7cb1e97
--- /dev/null
+++ b/packages/api/src/__tests__/assistant-tools-user-self-service-column-preferences.test.ts
@@ -0,0 +1,99 @@
+import { beforeEach, describe, expect, it, vi } from "vitest";
+import { SystemRole } from "@capakraken/shared";
+
+vi.mock("@capakraken/application", async (importOriginal) => {
+  const actual = await importOriginal<typeof import("@capakraken/application")>();
+  return {
+    ...actual,
+    getDashboardBudgetForecast: vi.fn().mockResolvedValue([]),
+    getDashboardPeakTimes: vi.fn().mockResolvedValue([]),
+    listAssignmentBookings: vi.fn().mockResolvedValue([]),
+  };
+});
+
+import { executeTool } from "../router/assistant-tools.js";
+import { createToolContext } from "./assistant-tools-user-self-service-test-helpers.js";
+
+describe("assistant user self-service column preferences tools", () => {
+  beforeEach(() => {
+    vi.clearAllMocks();
+  });
+
+  it("reads column preferences through the real user router path", async () => {
+    const db = {
+      user: {
+        findUnique: vi.fn().mockResolvedValue({
+          columnPreferences: {
+            resources: {
+              visible: ["name", "role"],
+              sort: { field: "name", dir: "asc" },
+            },
+          },
+        }),
+      },
+    };
+    const ctx = createToolContext(db, SystemRole.ADMIN);
+
+    const result = await executeTool("get_column_preferences", "{}", ctx);
+
+    expect(db.user.findUnique).toHaveBeenCalledWith({
+      where: { id: "user_1" },
+      select: { columnPreferences: true },
+    });
+    expect(JSON.parse(result.content)).toEqual({
+      resources: {
+        visible: ["name", "role"],
+        sort: { field: "name", dir: "asc" },
+      },
+    });
+  });
+
+  it("updates column preferences through the real user router path", async () => {
+    const db = {
+      user: {
+        findUnique: vi.fn().mockResolvedValue({
+          columnPreferences: {
+            resources: {
+              visible: ["name", "role"],
+              sort: { field: "name", dir: "asc" },
+              rowOrder: ["name", "role", "email"],
+            },
+          },
+        }),
+        update: vi.fn().mockResolvedValue({ id: "user_1" }),
+      },
+    };
+    const ctx = createToolContext(db, SystemRole.ADMIN);
+
+    const result = await executeTool(
+      "set_column_preferences",
+      JSON.stringify({
+        view: "resources",
+        visible: ["name", "email"],
+      }),
+      ctx,
+    );
+
+    expect(db.user.update).toHaveBeenCalledWith({
+      where: { id: "user_1" },
+      data: {
+        columnPreferences: {
+          resources: {
+            visible: ["name", "email"],
+            sort: { field: "name", dir: "asc" },
+            rowOrder: ["name", "role", "email"],
+          },
+        },
+      },
+    });
+    expect(JSON.parse(result.content)).toEqual({
+      success: true,
+      ok: true,
+      message: "Updated column preferences for resources.",
+    });
+    expect(result.action).toEqual({
+      type: "invalidate",
+      scope: ["user"],
+    });
+  });
+});
diff --git a/packages/api/src/__tests__/assistant-tools-user-self-service-dashboard-layout.test.ts b/packages/api/src/__tests__/assistant-tools-user-self-service-dashboard-layout.test.ts
new file mode 100644
index 0000000..d2ed82a
--- /dev/null
+++ b/packages/api/src/__tests__/assistant-tools-user-self-service-dashboard-layout.test.ts
@@ -0,0 +1,89 @@
+import { beforeEach, describe, expect, it, vi } from "vitest";
+import { SystemRole } from "@capakraken/shared";
+
+vi.mock("@capakraken/application", async (importOriginal) => {
+  const actual = await importOriginal<typeof import("@capakraken/application")>();
+  return {
+    ...actual,
+    getDashboardBudgetForecast: vi.fn().mockResolvedValue([]),
+    getDashboardPeakTimes: vi.fn().mockResolvedValue([]),
+    listAssignmentBookings: vi.fn().mockResolvedValue([]),
+  };
+});
+
+import { executeTool } from "../router/assistant-tools.js";
+import { createToolContext } from "./assistant-tools-user-self-service-test-helpers.js";
+
+describe("assistant user self-service dashboard layout tools", () => {
+  beforeEach(() => {
+    vi.clearAllMocks();
+  });
+
+  it("reads dashboard layout through the real user router path", async () => {
+    const db = {
+      user: {
+        findUnique: vi.fn().mockResolvedValue({
+          dashboardLayout: {
+            widgets: [
+              { id: "peakTimes", position: { x: 0, y: 0, w: 4, h: 3 } },
+            ],
+          },
+          updatedAt: new Date("2026-03-30T18:00:00.000Z"),
+        }),
+      },
+    };
+    const ctx = createToolContext(db, SystemRole.ADMIN);
+
+    const result = await executeTool("get_dashboard_layout", "{}", ctx);
+
+    expect(db.user.findUnique).toHaveBeenCalledWith({
+      where: { id: "user_1" },
+      select: { dashboardLayout: true, updatedAt: true },
+    });
+    expect(JSON.parse(result.content)).toEqual({
+      layout: {
+        version: 2,
+        gridCols: 12,
+        widgets: [],
+      },
+      updatedAt: "2026-03-30T18:00:00.000Z",
+    });
+  });
+
+  it("saves dashboard layout through the real user router path", async () => {
+    const db = {
+      user: {
+        update: vi.fn().mockResolvedValue({
+          updatedAt: new Date("2026-03-30T19:00:00.000Z"),
+        }),
+      },
+    };
+    const ctx = createToolContext(db, SystemRole.ADMIN);
+    const layout = {
+      version: 2,
+      gridCols: 12,
+      widgets: [],
+    };
+
+    const result = await executeTool(
+      "save_dashboard_layout",
+      JSON.stringify({ layout }),
+      ctx,
+    );
+
+    expect(db.user.update).toHaveBeenCalledWith({
+      where: { id: "user_1" },
+      data: { dashboardLayout: layout },
+      select: { updatedAt: true },
+    });
+    expect(JSON.parse(result.content)).toEqual({
+      success: true,
+      updatedAt: "2026-03-30T19:00:00.000Z",
+      message: "Saved dashboard layout.",
+    });
+    expect(result.action).toEqual({
+      type: "invalidate",
+      scope: ["dashboard"],
+    });
+  });
+});
diff --git a/packages/api/src/__tests__/assistant-tools-user-self-service-favorite-projects.test.ts b/packages/api/src/__tests__/assistant-tools-user-self-service-favorite-projects.test.ts
new file mode 100644
index 0000000..8a88f17
--- /dev/null
+++ b/packages/api/src/__tests__/assistant-tools-user-self-service-favorite-projects.test.ts
@@ -0,0 +1,106 @@
+import { beforeEach, describe, expect, it, vi } from "vitest";
+import { SystemRole } from "@capakraken/shared";
+
+vi.mock("@capakraken/application", async (importOriginal) => {
+  const actual = await importOriginal<typeof import("@capakraken/application")>();
+  return {
+    ...actual,
+    getDashboardBudgetForecast: vi.fn().mockResolvedValue([]),
+    getDashboardPeakTimes: vi.fn().mockResolvedValue([]),
+    listAssignmentBookings: vi.fn().mockResolvedValue([]),
+  };
+});
+
+import { executeTool } from "../router/assistant-tools.js";
+import { createToolContext } from "./assistant-tools-user-self-service-test-helpers.js";
+
+describe("assistant user self-service favorite project tools", () => {
+  beforeEach(() => {
+    vi.clearAllMocks();
+  });
+
+  it("reads favorite project ids through the real user router path", async () => {
+    const db = {
+      user: {
+        findUnique: vi.fn().mockResolvedValue({
+          favoriteProjectIds: ["project_1", "project_2"],
+        }),
+      },
+    };
+    const ctx = createToolContext(db, SystemRole.ADMIN);
+
+    const result = await executeTool("get_favorite_project_ids", "{}", ctx);
+
+    expect(db.user.findUnique).toHaveBeenCalledWith({
+      where: { id: "user_1" },
+      select: { favoriteProjectIds: true },
+    });
+    expect(JSON.parse(result.content)).toEqual(["project_1", "project_2"]);
+  });
+
+  it("adds a project to favorites through the real user router path", async () => {
+    const db = {
+      user: {
+        findUnique: vi.fn().mockResolvedValue({
+          favoriteProjectIds: ["project_1"],
+        }),
+        update: vi.fn().mockResolvedValue({}),
+      },
+    };
+    const ctx = createToolContext(db, SystemRole.ADMIN);
+
+    const result = await executeTool(
+      "toggle_favorite_project",
+      JSON.stringify({ projectId: "project_2" }),
+      ctx,
+    );
+
+    expect(db.user.update).toHaveBeenCalledWith({
+      where: { id: "user_1" },
+      data: { favoriteProjectIds: ["project_1", "project_2"] },
+    });
+    expect(JSON.parse(result.content)).toEqual({
+      success: true,
+      favoriteProjectIds: ["project_1", "project_2"],
+      added: true,
+      message: "Added project to favorites.",
+    });
+    expect(result.action).toEqual({
+      type: "invalidate",
+      scope: ["project"],
+    });
+  });
+
+  it("removes a project from favorites through the real user router path", async () => {
+    const db = {
+      user: {
+        findUnique: vi.fn().mockResolvedValue({
+          favoriteProjectIds: ["project_1", "project_2"],
+        }),
+        update: vi.fn().mockResolvedValue({}),
+      },
+    };
+    const ctx = createToolContext(db, SystemRole.ADMIN);
+
+    const result = await executeTool(
+      "toggle_favorite_project",
+      JSON.stringify({ projectId: "project_2" }),
+      ctx,
+    );
+
+    expect(db.user.update).toHaveBeenCalledWith({
+      where: { id: "user_1" },
+      data: { favoriteProjectIds: ["project_1"] },
+    });
+    expect(JSON.parse(result.content)).toEqual({
+      success: true,
+      favoriteProjectIds: ["project_1"],
+      added: false,
+      message: "Removed project from favorites.",
+    });
+    expect(result.action).toEqual({
+      type: "invalidate",
+      scope: ["project"],
+    });
+  });
+});
diff --git a/packages/api/src/__tests__/assistant-tools-user-self-service-mfa-enable.test.ts b/packages/api/src/__tests__/assistant-tools-user-self-service-mfa-enable.test.ts
new file mode 100644
index 0000000..5158d0c
--- /dev/null
+++ b/packages/api/src/__tests__/assistant-tools-user-self-service-mfa-enable.test.ts
@@ -0,0 +1,96 @@
+import { beforeEach, describe, expect, it, vi } from "vitest";
+import { SystemRole } from "@capakraken/shared";
+import {
+  createToolContext,
+  executeTool,
+  totpValidateMock,
+} from "./assistant-tools-user-self-service-mfa-test-helpers.js";
+
+describe("assistant user self-service MFA tools - enable flow", () => {
+  beforeEach(() => {
+    vi.clearAllMocks();
+    totpValidateMock.mockReset();
+  });
+
+  it("generates a TOTP secret through the real user router path", async () => {
+    const db = {
+      user: {
+        update: vi.fn().mockResolvedValue({}),
+      },
+    };
+    const ctx = createToolContext(db, SystemRole.ADMIN);
+
+    const result = await executeTool("generate_totp_secret", "{}", ctx);
+
+    expect(db.user.update).toHaveBeenCalledWith({
+      where: { id: "user_1" },
+      data: { totpSecret: "MOCKSECRET" },
+    });
+    expect(JSON.parse(result.content)).toEqual({
+      success: true,
+      secret: "MOCKSECRET",
+      uri: "otpauth://mock",
+      message: "Generated a new MFA TOTP secret.",
+    });
+    expect(result.action).toEqual({
+      type: "invalidate",
+      scope: ["user"],
+    });
+  });
+
+  it("enables TOTP through the real user router path when the token is valid", async () => {
+    totpValidateMock.mockReturnValue(0);
+
+    const db = {
+      user: {
+        findUnique: vi.fn().mockResolvedValue({
+          id: "user_1",
+          name: "Assistant User",
+          email: "assistant@example.com",
+          totpSecret: "MOCKSECRET",
+          totpEnabled: false,
+        }),
+        update: vi.fn().mockResolvedValue({}),
+      },
+      auditLog: {
+        create: vi.fn().mockResolvedValue({ id: "audit_1" }),
+      },
+    };
+    const ctx = createToolContext(db, SystemRole.ADMIN);
+
+    const result = await executeTool(
+      "verify_and_enable_totp",
+      JSON.stringify({ token: "123456" }),
+      ctx,
+    );
+
+    expect(db.user.findUnique).toHaveBeenCalledWith({
+      where: { id: "user_1" },
+      select: { id: true, name: true, email: true, totpSecret: true, totpEnabled: true },
+    });
+    expect(db.user.update).toHaveBeenCalledWith({
+      where: { id: "user_1" },
+      data: { totpEnabled: true },
+    });
+    expect(db.auditLog.create).toHaveBeenCalledWith({
+      data: expect.objectContaining({
+        entityType: "User",
+        entityId: "user_1",
+        action: "UPDATE",
+        userId: "user_1",
+        source: "ui",
+        entityName: "Assistant User (assistant@example.com)",
+        summary: "Enabled TOTP MFA",
+      }),
+    });
+    expect(JSON.parse(result.content)).toEqual({
+      success: true,
+      enabled: true,
+      message: "Enabled MFA TOTP.",
+    });
+    expect(result.action).toEqual({
+      type: "invalidate",
+      scope: ["user"],
+    });
+  });
+});
diff --git a/packages/api/src/__tests__/assistant-tools-user-self-service-mfa-errors.test.ts b/packages/api/src/__tests__/assistant-tools-user-self-service-mfa-errors.test.ts
new file mode 100644
index 0000000..05b6b63
--- /dev/null
+++ b/packages/api/src/__tests__/assistant-tools-user-self-service-mfa-errors.test.ts
@@ -0,0 +1,121 @@
+import { beforeEach, describe, expect, it, vi } from "vitest";
+import { SystemRole } from "@capakraken/shared";
+import {
+  createToolContext,
+  executeTool,
+  totpValidateMock,
+} from "./assistant-tools-user-self-service-mfa-test-helpers.js";
+
+describe("assistant user self-service MFA tools - errors", () => {
+  beforeEach(() => {
+    vi.clearAllMocks();
+    totpValidateMock.mockReset();
+  });
+
+  it("returns a stable error when enabling TOTP without a generated secret", async () => {
+    const ctx = createToolContext(
+      {
+        user: {
+          findUnique: vi.fn().mockResolvedValue({
+            id: "user_1",
+            name: "Assistant User",
+            email: "assistant@example.com",
+            totpSecret: null,
+            totpEnabled: false,
+          }),
+        },
+      },
+      SystemRole.ADMIN,
+    );
+
+    const result = await executeTool(
+      "verify_and_enable_totp",
+      JSON.stringify({ token: "123456" }),
+      ctx,
+    );
+
+    expect(JSON.parse(result.content)).toEqual({
+      error: "No TOTP secret generated. Call generate_totp_secret first.",
+    });
+  });
+
+  it("returns a stable error when enabling TOTP for a missing user", async () => {
+    const ctx = createToolContext(
+      {
+        user: {
+          findUnique: vi.fn().mockResolvedValue(null),
+        },
+      },
+      SystemRole.ADMIN,
+    );
+
+    const result = await executeTool(
+      "verify_and_enable_totp",
+      JSON.stringify({ token: "123456" }),
+      ctx,
+    );
+
+    expect(JSON.parse(result.content)).toEqual({
+      error: "User not found with the given criteria.",
+    });
+  });
+
+  it("returns a stable error when enabling TOTP that is already enabled", async () => {
+    const ctx = createToolContext(
+      {
+        user: {
+          findUnique: vi.fn().mockResolvedValue({
+            id: "user_1",
+            name: "Assistant User",
+            email: "assistant@example.com",
+            totpSecret: "MOCKSECRET",
+            totpEnabled: true,
+          }),
+        },
+      },
+      SystemRole.ADMIN,
+    );
+
+    const result = await executeTool(
+      "verify_and_enable_totp",
+      JSON.stringify({ token: "123456" }),
+      ctx,
+    );
+
+    expect(JSON.parse(result.content)).toEqual({
+      error: "TOTP is already enabled.",
+    });
+  });
+
+  it("returns a stable error when a provided TOTP token is invalid", async () => {
+    totpValidateMock.mockReturnValue(null);
+
+    const update = vi.fn();
+    const ctx = createToolContext(
+      {
+        user: {
+          findUnique: vi.fn().mockResolvedValue({
+            id: "user_1",
+            name: "Assistant User",
+            email: "assistant@example.com",
+            totpSecret: "MOCKSECRET",
+            totpEnabled: false,
+          }),
+          update,
+        },
+      },
+      SystemRole.ADMIN,
+    );
+
+    const result = await executeTool(
+      "verify_and_enable_totp",
+      JSON.stringify({ token: "123456" }),
+      ctx,
+    );
+
+    expect(update).not.toHaveBeenCalled();
+    expect(JSON.parse(result.content)).toEqual({
+      error: "Invalid TOTP token.",
+    });
+  });
+});
diff --git a/packages/api/src/__tests__/assistant-tools-user-self-service-mfa-status.test.ts b/packages/api/src/__tests__/assistant-tools-user-self-service-mfa-status.test.ts
new file mode 100644
index 0000000..13751cc
--- /dev/null
+++ b/packages/api/src/__tests__/assistant-tools-user-self-service-mfa-status.test.ts
@@ -0,0 +1,52 @@
+import { beforeEach, describe, expect, it, vi } from "vitest";
+import { SystemRole } from "@capakraken/shared";
+import {
+  createToolContext,
+  executeTool,
+  totpValidateMock,
+} from "./assistant-tools-user-self-service-mfa-test-helpers.js";
+
+describe("assistant user self-service MFA tools - status", () => {
+  beforeEach(() => {
+    vi.clearAllMocks();
+    totpValidateMock.mockReset();
+  });
+
+  it("returns MFA status through the real user router path", async () => {
+    const db = {
+      user: {
+        findUnique: vi.fn().mockResolvedValue({
+          totpEnabled: true,
+        }),
+      },
+    };
+    const ctx = createToolContext(db, SystemRole.ADMIN);
+
+    const result = await executeTool("get_mfa_status", "{}", ctx);
+
+    expect(db.user.findUnique).toHaveBeenCalledWith({
+      where: { id: "user_1" },
+      select: { totpEnabled: true },
+    });
+    expect(JSON.parse(result.content)).toEqual({
+      totpEnabled: true,
+    });
+  });
+
+  it("returns a stable error when reading MFA status for a missing user", async () => {
+    const ctx = createToolContext(
+      {
+        user: {
+          findUnique: vi.fn().mockResolvedValue(null),
+        },
+      },
+      SystemRole.ADMIN,
+    );
+
+    const result = await executeTool("get_mfa_status", "{}", ctx);
+
+    expect(JSON.parse(result.content)).toEqual({
+      error: "User not found with the given criteria.",
+    });
+  });
+});
diff --git a/packages/api/src/__tests__/assistant-tools-user-self-service-mfa-test-helpers.ts b/packages/api/src/__tests__/assistant-tools-user-self-service-mfa-test-helpers.ts
new file mode 100644
index 0000000..4df8f8e
--- /dev/null
+++ b/packages/api/src/__tests__/assistant-tools-user-self-service-mfa-test-helpers.ts
@@ -0,0 +1,49 @@
+import { vi } from "vitest";
+
+const hoistedMocks = vi.hoisted(() => ({
+  totpValidateMock: vi.fn(),
+}));
+
+export const totpValidateMock = hoistedMocks.totpValidateMock;
+
+vi.mock("@capakraken/application", async (importOriginal) => {
+  const actual = await importOriginal<typeof import("@capakraken/application")>();
+  return {
+    ...actual,
+    getDashboardBudgetForecast: vi.fn().mockResolvedValue([]),
+    getDashboardPeakTimes: vi.fn().mockResolvedValue([]),
+    listAssignmentBookings: vi.fn().mockResolvedValue([]),
+  };
+});
+
+vi.mock("otpauth", () => {
+  class Secret {
+    base32: string;
+
+    constructor() {
+      this.base32 = "MOCKSECRET";
+    }
+
+    static fromBase32(value: string) {
+      return value;
+    }
+  }
+
+  class TOTP {
+    validate(args: { token: string; window: number }) {
+      return totpValidateMock(args);
+    }
+
+    toString() {
+      return "otpauth://mock";
+    }
+  }
+
+  return { Secret, TOTP };
+});
+
+import { executeTool as executeAssistantTool } from "../router/assistant-tools.js";
+
+export { createToolContext } from "./assistant-tools-user-self-service-test-helpers.js";
+
+export const executeTool = executeAssistantTool;
diff --git a/packages/api/src/__tests__/assistant-tools-user-self-service-profile.test.ts b/packages/api/src/__tests__/assistant-tools-user-self-service-profile.test.ts
new file mode 100644
index 0000000..db47b1e
--- /dev/null
+++ b/packages/api/src/__tests__/assistant-tools-user-self-service-profile.test.ts
@@ -0,0 +1,73 @@
+import { beforeEach, describe, expect, it, vi } from "vitest";
+import { SystemRole } from "@capakraken/shared";
+
+vi.mock("@capakraken/application", async (importOriginal) => {
+  const actual = await importOriginal<typeof import("@capakraken/application")>();
+  return {
+    ...actual,
+    getDashboardBudgetForecast: vi.fn().mockResolvedValue([]),
+    getDashboardPeakTimes: vi.fn().mockResolvedValue([]),
+    listAssignmentBookings: vi.fn().mockResolvedValue([]),
+  };
+});
+
+import { executeTool } from "../router/assistant-tools.js";
+import { createToolContext } from "./assistant-tools-user-self-service-test-helpers.js";
+
+describe("assistant user self-service profile tools", () => {
+  beforeEach(() => {
+    vi.clearAllMocks();
+  });
+
+  it("reads the current user profile through the real user router path", async () => {
+    const db = {
+      user: {
+        findUnique: vi.fn().mockResolvedValue({
+          id: "user_1",
+          name: "Assistant User",
+          email: "assistant@example.com",
+          systemRole: SystemRole.ADMIN,
+          permissionOverrides: null,
+          createdAt: new Date("2026-03-28T10:00:00.000Z"),
+        }),
+      },
+    };
+    const ctx = createToolContext(db, SystemRole.ADMIN);
+
+    const result = await executeTool("get_current_user", "{}", ctx);
+
+    expect(db.user.findUnique).toHaveBeenCalledWith({
+      where: { id: "user_1" },
+      select: {
+        id: true,
+        name: true,
+        email: true,
+        systemRole: true,
+        permissionOverrides: true,
+        createdAt: true,
+      },
+    });
+    expect(JSON.parse(result.content)).toEqual({
+      id: "user_1",
+      name: "Assistant User",
+      email: "assistant@example.com",
+      systemRole: SystemRole.ADMIN,
+      permissionOverrides: null,
+      createdAt: "2026-03-28T10:00:00.000Z",
+    });
+  });
+
+  it("returns a stable error when reading the current user profile for a missing user", async () => {
+    const ctx = createToolContext({
+      user: {
+        findUnique: vi.fn().mockResolvedValue(null),
+      },
+    }, SystemRole.ADMIN);
+
+    const result = await executeTool("get_current_user", "{}", ctx);
+
+    expect(JSON.parse(result.content)).toEqual({
+      error: "User not found with the given criteria.",
+    });
+  });
+});
diff --git a/packages/api/src/__tests__/assistant-tools-user-self-service-test-helpers.ts b/packages/api/src/__tests__/assistant-tools-user-self-service-test-helpers.ts
new file mode 100644
index 0000000..12f0e05
--- /dev/null
+++ b/packages/api/src/__tests__/assistant-tools-user-self-service-test-helpers.ts
@@ -0,0 +1,25 @@
+import { SystemRole } from "@capakraken/shared";
+
+import type { ToolContext } from "../router/assistant-tools.js";
+
+export function createToolContext(
+  db: Record<string, unknown>,
+  userRole: SystemRole = SystemRole.USER,
+): ToolContext {
+  return {
+    db: db as ToolContext["db"],
+    userId: "user_1",
+    userRole,
+    permissions: new Set(),
+    session: {
+      user: { email: "assistant@example.com", name: "Assistant User", image: null },
+      expires: "2026-03-29T00:00:00.000Z",
+    },
+    dbUser: {
+      id: "user_1",
+      systemRole: userRole,
+      permissionOverrides: null,
+    },
+    roleDefaults: null,
+  };
+}
diff --git a/packages/api/src/__tests__/user-router-auth.test.ts b/packages/api/src/__tests__/user-router-auth.test.ts
index f6e0e3b..8b2ab7a 100644
--- a/packages/api/src/__tests__/user-router-auth.test.ts
+++ b/packages/api/src/__tests__/user-router-auth.test.ts
@@ -85,6 +85,82 @@ describe("user router authorization", () => {
     expect(update).not.toHaveBeenCalled();
   });
 
+  it("requires authentication for dashboard layout saves", async () => {
+    const update = vi.fn();
+    const caller = createCaller(createContext({
+      user: {
+        update,
+      },
+    }, { session: false }));
+
+    await expect(caller.saveDashboardLayout({
+      layout: { version: 2, gridCols: 12, widgets: [] },
+    })).rejects.toMatchObject({
+      code: "UNAUTHORIZED",
+      message: "Authentication required",
+    });
+
+    expect(update).not.toHaveBeenCalled();
+  });
+
+  it("requires authentication for favorite project reads", async () => {
+    const findUnique = vi.fn();
+    const caller = createCaller(createContext({
+      user: {
+        findUnique,
+      },
+    }, { session: false }));
+
+    await expect(caller.getFavoriteProjectIds()).rejects.toMatchObject({
+      code: "UNAUTHORIZED",
+      message: "Authentication required",
+    });
+
+    expect(findUnique).not.toHaveBeenCalled();
+  });
+
+  it("requires authentication for column preference reads and writes", async () => {
+    const findUnique = vi.fn();
+    const update = vi.fn();
+    const caller = createCaller(createContext({
+      user: {
+        findUnique,
+        update,
+      },
+    }, { session: false }));
+
+    await expect(caller.getColumnPreferences()).rejects.toMatchObject({
+      code: "UNAUTHORIZED",
+      message: "Authentication required",
+    });
+    await expect(caller.setColumnPreferences({
+      view: "resources",
+      visible: ["name"],
+    })).rejects.toMatchObject({
+      code: "UNAUTHORIZED",
+      message: "Authentication required",
+    });
+
+    expect(findUnique).not.toHaveBeenCalled();
+    expect(update).not.toHaveBeenCalled();
+  });
+
+  it("requires authentication for MFA status lookups", async () => {
+    const findUniqueOrThrow = vi.fn();
+    const caller = createCaller(createContext({
+      user: {
+        findUniqueOrThrow,
+      },
+    }, { session: false }));
+
+    await expect(caller.getMfaStatus()).rejects.toMatchObject({
+      code: "UNAUTHORIZED",
+      message: "Authentication required",
+    });
+
+    expect(findUniqueOrThrow).not.toHaveBeenCalled();
+  });
+
   it("forbids regular users from listing assignable users", async () => {
     const findMany = vi.fn();
     const caller = createCaller(createContext({
@@ -140,6 +216,49 @@ describe("user router authorization", () => {
     expect(findUnique).not.toHaveBeenCalled();
   });
 
+  it("forbids non-admin users from setting explicit permission overrides", async () => {
+    const findUnique = vi.fn();
+    const update = vi.fn();
+    const caller = createCaller(createContext({
+      user: {
+        findUnique,
+        update,
+      },
+    }, { role: SystemRole.MANAGER }));
+
+    await expect(caller.setPermissions({
+      userId: "user_2",
+      overrides: {
+        granted: ["manageProjects"],
+      },
+    })).rejects.toMatchObject({
+      code: "FORBIDDEN",
+      message: "Admin role required",
+    });
+
+    expect(findUnique).not.toHaveBeenCalled();
+    expect(update).not.toHaveBeenCalled();
+  });
+
+  it("forbids non-admin users from resetting permission overrides", async () => {
+    const findUnique = vi.fn();
+    const update = vi.fn();
+    const caller = createCaller(createContext({
+      user: {
+        findUnique,
+        update,
+      },
+    }, { role: SystemRole.MANAGER }));
+
+    await expect(caller.resetPermissions({ userId: "user_2" })).rejects.toMatchObject({
+      code: "FORBIDDEN",
+      message: "Admin role required",
+    });
+
+    expect(findUnique).not.toHaveBeenCalled();
+    expect(update).not.toHaveBeenCalled();
+  });
+
   it("forbids non-admin users from disabling TOTP for other users", async () => {
     const findUnique = vi.fn();
     const caller = createCaller(createContext({
@@ -186,15 +305,39 @@ describe("user router authorization", () => {
     expect(update).not.toHaveBeenCalled();
   });
 
+  it("forbids non-admin users from auto-linking users by email", async () => {
+    const userFindMany = vi.fn();
+    const resourceFindFirst = vi.fn();
+    const resourceUpdate = vi.fn();
+    const caller = createCaller(createContext({
+      user: {
+        findMany: userFindMany,
+      },
+      resource: {
+        findFirst: resourceFindFirst,
+        update: resourceUpdate,
+      },
+    }, { role: SystemRole.MANAGER }));
+
+    await expect(caller.autoLinkAllByEmail()).rejects.toMatchObject({
+      code: "FORBIDDEN",
+      message: "Admin role required",
+    });
+
+    expect(userFindMany).not.toHaveBeenCalled();
+    expect(resourceFindFirst).not.toHaveBeenCalled();
+    expect(resourceUpdate).not.toHaveBeenCalled();
+  });
+
   it("keeps TOTP verification public for the login flow", async () => {
-    const findUniqueOrThrow = vi.fn().mockResolvedValue({
+    const findUnique = vi.fn().mockResolvedValue({
       id: "user_1",
       totpEnabled: false,
       totpSecret: null,
     });
     const caller = createCaller(createContext({
       user: {
-        findUniqueOrThrow,
+        findUnique,
       },
     }, { session: false }));
 
@@ -203,7 +346,7 @@ describe("user router authorization", () => {
       message: "TOTP is not enabled for this user.",
     });
 
-    expect(findUniqueOrThrow).toHaveBeenCalledWith({
+    expect(findUnique).toHaveBeenCalledWith({
       where: { id: "user_1" },
       select: { id: true, totpSecret: true, totpEnabled: true },
     });
diff --git a/packages/api/src/__tests__/user-router.test.ts b/packages/api/src/__tests__/user-router.test.ts
index a222af8..ead57c2 100644
--- a/packages/api/src/__tests__/user-router.test.ts
+++ b/packages/api/src/__tests__/user-router.test.ts
@@ -1,8 +1,51 @@
-import { SystemRole } from "@capakraken/shared";
+import { Prisma } from "@capakraken/db";
+import { resolvePermissions, SystemRole } from "@capakraken/shared";
 import { describe, expect, it, vi } from "vitest";
 import { userRouter } from "../router/user.js";
 import { createCallerFactory } from "../trpc.js";
 
+const { totpValidateMock } = vi.hoisted(() => ({
+  totpValidateMock: vi.fn(),
+}));
+
+const { argon2HashMock } = vi.hoisted(() => ({
+  argon2HashMock: vi.fn(),
+}));
+
+vi.mock("../lib/audit.js", () => ({
+  createAuditEntry: vi.fn().mockResolvedValue(undefined),
+}));
+
+vi.mock("@node-rs/argon2", () => ({
+  hash: argon2HashMock,
+}));
+
+vi.mock("otpauth", () => {
+  class Secret {
+    base32: string;
+
+    constructor() {
+      this.base32 = "MOCKSECRET";
+    }
+
+    static fromBase32(value: string) {
+      return value;
+    }
+  }
+
+  class TOTP {
+    validate(args: { token: string; window: number }) {
+      return totpValidateMock(args);
+    }
+
+    toString() {
+      return "otpauth://mock";
+    }
+  }
+
+  return { Secret, TOTP };
+});
+
 const createCaller = createCallerFactory(userRouter);
 
 function createAdminCaller(db: Record<string, unknown>) {
@@ -59,7 +102,6 @@ describe("user.linkResource", () => {
     const userFindUnique = vi.fn().mockResolvedValue({ id: "user_1" });
     const resourceFindUnique = vi.fn().mockResolvedValue(null);
     const updateMany = vi.fn();
-    const update = vi.fn();
     const caller = createAdminCaller({
       user: {
         findUnique: userFindUnique,
@@ -67,7 +109,6 @@ describe("user.linkResource", () => {
       resource: {
         findUnique: resourceFindUnique,
         updateMany,
-        update,
       },
     });
 
@@ -81,17 +122,42 @@ describe("user.linkResource", () => {
 
     expect(resourceFindUnique).toHaveBeenCalledWith({
       where: { id: "missing_resource" },
-      select: { id: true },
+      select: { id: true, userId: true },
     });
     expect(updateMany).not.toHaveBeenCalled();
-    expect(update).not.toHaveBeenCalled();
   });
 
-  it("unlinks existing assignments before linking the requested resource", async () => {
+  it("returns CONFLICT when the requested resource is already linked to another user", async () => {
     const userFindUnique = vi.fn().mockResolvedValue({ id: "user_1" });
-    const resourceFindUnique = vi.fn().mockResolvedValue({ id: "resource_1" });
-    const updateMany = vi.fn().mockResolvedValue({ count: 1 });
-    const update = vi.fn().mockResolvedValue({ id: "resource_1", userId: "user_1" });
+    const resourceFindUnique = vi.fn().mockResolvedValue({ id: "resource_1", userId: "user_2" });
+    const updateMany = vi.fn();
+    const caller = createAdminCaller({
+      user: {
+        findUnique: userFindUnique,
+      },
+      resource: {
+        findUnique: resourceFindUnique,
+        updateMany,
+      },
+    });
+
+    await expect(caller.linkResource({
+      userId: "user_1",
+      resourceId: "resource_1",
+    })).rejects.toMatchObject({
+      code: "CONFLICT",
+      message: "Resource is already linked to another user",
+    });
+
+    expect(updateMany).not.toHaveBeenCalled();
+  });
+
+  it("unlinks existing assignments before linking the requested resource", async () => {
+    const userFindUnique = vi.fn().mockResolvedValue({ id: "user_1" });
+    const resourceFindUnique = vi.fn().mockResolvedValue({ id: "resource_1", userId: null });
+    const updateMany = vi.fn()
+      .mockResolvedValueOnce({ count: 1 })
+      .mockResolvedValueOnce({ count: 1 });
     const caller = createAdminCaller({
       user: {
         findUnique: userFindUnique,
@@ -99,7 +165,6 @@ describe("user.linkResource", () => {
       resource: {
         findUnique: resourceFindUnique,
         updateMany,
-        update,
       },
     });
 
@@ -109,13 +174,850 @@ describe("user.linkResource", () => {
     });
 
     expect(result).toEqual({ success: true });
+    expect(updateMany).toHaveBeenNthCalledWith(1, {
+      where: {
+        userId: "user_1",
+        NOT: { id: "resource_1" },
+      },
+      data: { userId: null },
+    });
+    expect(updateMany).toHaveBeenNthCalledWith(2, {
+      where: {
+        id: "resource_1",
+        OR: [{ userId: null }, { userId: "user_1" }],
+      },
+      data: { userId: "user_1" },
+    });
+  });
+
+  it("unlinks a user without checking or updating a replacement resource", async () => {
+    const userFindUnique = vi.fn().mockResolvedValue({ id: "user_1" });
+    const resourceFindUnique = vi.fn();
+    const updateMany = vi.fn().mockResolvedValue({ count: 1 });
+    const caller = createAdminCaller({
+      user: {
+        findUnique: userFindUnique,
+      },
+      resource: {
+        findUnique: resourceFindUnique,
+        updateMany,
+      },
+    });
+
+    const result = await caller.linkResource({
+      userId: "user_1",
+      resourceId: null,
+    });
+
+    expect(result).toEqual({ success: true });
+    expect(userFindUnique).toHaveBeenCalledWith({
+      where: { id: "user_1" },
+      select: { id: true },
+    });
+    expect(resourceFindUnique).not.toHaveBeenCalled();
     expect(updateMany).toHaveBeenCalledWith({
       where: { userId: "user_1" },
       data: { userId: null },
     });
-    expect(update).toHaveBeenCalledWith({
-      where: { id: "resource_1" },
-      data: { userId: "user_1" },
+  });
+
+  it("returns CONFLICT when the resource link changes between validation and update", async () => {
+    const userFindUnique = vi.fn().mockResolvedValue({ id: "user_1" });
+    const resourceFindUnique = vi.fn().mockResolvedValue({ id: "resource_1", userId: null });
+    const updateMany = vi.fn()
+      .mockResolvedValueOnce({ count: 0 })
+      .mockResolvedValueOnce({ count: 0 });
+    const caller = createAdminCaller({
+      user: {
+        findUnique: userFindUnique,
+      },
+      resource: {
+        findUnique: resourceFindUnique,
+        updateMany,
+      },
+    });
+
+    await expect(caller.linkResource({
+      userId: "user_1",
+      resourceId: "resource_1",
+    })).rejects.toMatchObject({
+      code: "CONFLICT",
+      message: "Resource link changed during update. Please retry.",
+    });
+  });
+});
+
+describe("user admin account management", () => {
+  it("counts users active within the last five minutes", async () => {
+    const nowSpy = vi.spyOn(Date, "now").mockReturnValue(new Date("2026-03-30T20:00:00.000Z").valueOf());
+    const count = vi.fn().mockResolvedValue(4);
+    const caller = createAdminCaller({
+      user: {
+        count,
+      },
+    });
+
+    const result = await caller.activeCount();
+
+    expect(result).toEqual({ count: 4 });
+    expect(count).toHaveBeenCalledWith({
+      where: {
+        lastActiveAt: { gte: new Date("2026-03-30T19:55:00.000Z") },
+      },
+    });
+
+    nowSpy.mockRestore();
+  });
+
+  it("hashes and stores a replacement password for an existing user", async () => {
+    argon2HashMock.mockReset();
+    argon2HashMock.mockResolvedValue("hashed-secret");
+
+    const findUnique = vi.fn().mockResolvedValue({
+      id: "user_2",
+      name: "Alice",
+      email: "alice@example.com",
+    });
+    const update = vi.fn().mockResolvedValue({});
+    const caller = createAdminCaller({
+      user: {
+        findUnique,
+        update,
+      },
+    });
+
+    const result = await caller.setPassword({
+      userId: "user_2",
+      password: "secret123",
+    });
+
+    expect(result).toEqual({ success: true });
+    expect(argon2HashMock).toHaveBeenCalledWith("secret123");
+    expect(update).toHaveBeenCalledWith({
+      where: { id: "user_2" },
+      data: { passwordHash: "hashed-secret" },
+    });
+  });
+
+  it("updates the selected user's display name", async () => {
+    const findUnique = vi.fn().mockResolvedValue({
+      id: "user_2",
+      name: "Alice",
+      email: "alice@example.com",
+    });
+    const update = vi.fn().mockResolvedValue({
+      id: "user_2",
+      name: "Alice Updated",
+      email: "alice@example.com",
+    });
+    const caller = createAdminCaller({
+      user: {
+        findUnique,
+        update,
+      },
+    });
+
+    const result = await caller.updateName({
+      id: "user_2",
+      name: "Alice Updated",
+    });
+
+    expect(result).toEqual({
+      id: "user_2",
+      name: "Alice Updated",
+      email: "alice@example.com",
+    });
+    expect(findUnique).toHaveBeenCalledWith({
+      where: { id: "user_2" },
+      select: { id: true, name: true, email: true },
+    });
+    expect(update).toHaveBeenCalledWith({
+      where: { id: "user_2" },
+      data: { name: "Alice Updated" },
+      select: { id: true, name: true, email: true },
+    });
+  });
+});
+
+describe("user.autoLinkAllByEmail", () => {
+  it("links only users with an unclaimed resource that matches their email", async () => {
+    const userFindMany = vi.fn().mockResolvedValue([
+      { id: "user_1", email: "alice@example.com" },
+      { id: "user_2", email: "bob@example.com" },
+      { id: "user_3", email: "carol@example.com" },
+    ]);
+    const resourceFindFirst = vi
+      .fn()
+      .mockResolvedValueOnce({ id: "resource_1" })
+      .mockResolvedValueOnce(null)
+      .mockResolvedValueOnce({ id: "resource_3" });
+    const resourceUpdate = vi.fn().mockResolvedValue({});
+    const caller = createAdminCaller({
+      user: {
+        findMany: userFindMany,
+      },
+      resource: {
+        findFirst: resourceFindFirst,
+        update: resourceUpdate,
+      },
+    });
+
+    const result = await caller.autoLinkAllByEmail();
+
+    expect(result).toEqual({ linked: 2, checked: 3 });
+    expect(userFindMany).toHaveBeenCalledWith({
+      where: { resource: null },
+      select: { id: true, email: true },
+    });
+    expect(resourceFindFirst).toHaveBeenNthCalledWith(1, {
+      where: { email: "alice@example.com", userId: null },
+      select: { id: true },
+    });
+    expect(resourceFindFirst).toHaveBeenNthCalledWith(2, {
+      where: { email: "bob@example.com", userId: null },
+      select: { id: true },
+    });
+    expect(resourceFindFirst).toHaveBeenNthCalledWith(3, {
+      where: { email: "carol@example.com", userId: null },
+      select: { id: true },
+    });
+    expect(resourceUpdate).toHaveBeenCalledTimes(2);
+    expect(resourceUpdate).toHaveBeenNthCalledWith(1, {
+      where: { id: "resource_1" },
+      data: { userId: "user_1" },
+    });
+    expect(resourceUpdate).toHaveBeenNthCalledWith(2, {
+      where: { id: "resource_3" },
+      data: { userId: "user_3" },
+    });
+  });
+});
+
+describe("user permission overrides", () => {
+  it("stores explicit permission overrides for a user", async () => {
+    const before = {
+      id: "user_2",
+      name: "Alice",
+      email: "alice@example.com",
+      permissionOverrides: null,
+    };
+    const updated = {
+      id: "user_2",
+      permissionOverrides: {
+        granted: ["manageProjects"],
+        denied: ["viewCosts"],
+        chapterIds: ["chapter_design"],
+      },
+    };
+    const findUnique = vi.fn().mockResolvedValue(before);
+    const update = vi.fn().mockResolvedValue(updated);
+    const caller = createAdminCaller({
+      user: {
+        findUnique,
+        update,
+      },
+    });
+
+    const overrides = {
+      granted: ["manageProjects"],
+      denied: ["viewCosts"],
+      chapterIds: ["chapter_design"],
+    };
+    const result = await caller.setPermissions({
+      userId: "user_2",
+      overrides,
+    });
+
+    expect(result).toEqual(updated);
+    expect(findUnique).toHaveBeenCalledWith({
+      where: { id: "user_2" },
+      select: { id: true, name: true, email: true, permissionOverrides: true },
+    });
+    expect(update).toHaveBeenCalledWith({
+      where: { id: "user_2" },
+      data: { permissionOverrides: overrides },
+    });
+  });
+
+  it("resets permission overrides back to role defaults", async () => {
+    const before = {
+      id: "user_2",
+      name: "Alice",
+      email: "alice@example.com",
+      permissionOverrides: {
+        granted: ["manageProjects"],
+        denied: ["viewCosts"],
+      },
+    };
+    const updated = {
+      id: "user_2",
+      permissionOverrides: null,
+    };
+    const findUnique = vi.fn().mockResolvedValue(before);
+    const update = vi.fn().mockResolvedValue(updated);
+    const caller = createAdminCaller({
+      user: {
+        findUnique,
+        update,
+      },
+    });
+
+    const result = await caller.resetPermissions({ userId: "user_2" });
+
+    expect(result).toEqual(updated);
+    expect(findUnique).toHaveBeenCalledWith({
+      where: { id: "user_2" },
+      select: { id: true, name: true, email: true, permissionOverrides: true },
+    });
+    expect(update).toHaveBeenCalledWith({
+      where: { id: "user_2" },
+      data: { permissionOverrides: Prisma.DbNull },
+    });
+  });
+
+  it("returns resolved effective permissions together with stored overrides", async () => {
+    const overrides = {
+      granted: ["manageProjects"],
+      denied: ["viewCosts"],
+      chapterIds: ["chapter_design"],
+    };
+    const findUnique = vi.fn().mockResolvedValue({
+      systemRole: SystemRole.MANAGER,
+      permissionOverrides: overrides,
+    });
+    const caller = createAdminCaller({
+      user: {
+        findUnique,
+      },
+    });
+
+    const result = await caller.getEffectivePermissions({ userId: "user_2" });
+
+    expect(findUnique).toHaveBeenCalledWith({
+      where: { id: "user_2" },
+      select: { systemRole: true, permissionOverrides: true },
+    });
+    expect(result).toEqual({
+      systemRole: SystemRole.MANAGER,
+      effectivePermissions: Array.from(resolvePermissions(SystemRole.MANAGER, overrides)),
+      overrides,
+    });
+  });
+});
+
+describe("user profile and TOTP self-service", () => {
+  it("returns the authenticated user profile by db user id", async () => {
+    const findUnique = vi.fn().mockResolvedValue({
+      id: "user_admin",
+      name: "Admin",
+      email: "admin@example.com",
+      systemRole: SystemRole.ADMIN,
+      permissionOverrides: null,
+      createdAt: new Date("2026-03-30T08:00:00.000Z"),
+    });
+    const caller = createAdminCaller({
+      user: {
+        findUnique,
+      },
+    });
+
+    const result = await caller.me();
+
+    expect(findUnique).toHaveBeenCalledWith({
+      where: { id: "user_admin" },
+      select: {
+        id: true,
+        name: true,
+        email: true,
+        systemRole: true,
+        permissionOverrides: true,
+        createdAt: true,
+      },
+    });
+    expect(result).toEqual({
+      id: "user_admin",
+      name: "Admin",
+      email: "admin@example.com",
+      systemRole: SystemRole.ADMIN,
+      permissionOverrides: null,
+      createdAt: new Date("2026-03-30T08:00:00.000Z"),
+    });
+  });
+
+  it("uses the db user id for self-service profile reads even when the session email is stale", async () => {
+    const findUnique = vi.fn().mockResolvedValue({
+      id: "user_admin",
+      name: "Admin",
+      email: "admin@example.com",
+      systemRole: SystemRole.ADMIN,
+      permissionOverrides: null,
+      createdAt: new Date("2026-03-30T08:00:00.000Z"),
+    });
+    const caller = createCaller({
+      session: {
+        user: { email: "stale@example.com", name: "Admin", image: null },
+        expires: "2099-01-01T00:00:00.000Z",
+      },
+      db: {
+        user: {
+          findUnique,
+        },
+      } as never,
+      dbUser: {
+        id: "user_admin",
+        systemRole: SystemRole.ADMIN,
+        permissionOverrides: null,
+      },
+      roleDefaults: null,
+    });
+
+    await caller.me();
+
+    expect(findUnique).toHaveBeenCalledWith({
+      where: { id: "user_admin" },
+      select: {
+        id: true,
+        name: true,
+        email: true,
+        systemRole: true,
+        permissionOverrides: true,
+        createdAt: true,
+      },
+    });
+  });
+
+  it("stores a new TOTP secret for the current user and returns the enrollment URI", async () => {
+    const update = vi.fn().mockResolvedValue({});
+    const caller = createAdminCaller({
+      user: {
+        update,
+      },
+    });
+
+    const result = await caller.generateTotpSecret();
+
+    expect(update).toHaveBeenCalledWith({
+      where: { id: "user_admin" },
+      data: { totpSecret: "MOCKSECRET" },
+    });
+    expect(result).toEqual({
+      secret: "MOCKSECRET",
+      uri: "otpauth://mock",
+    });
+  });
+
+  it("rejects enabling TOTP when no secret was generated", async () => {
+    const findUnique = vi.fn().mockResolvedValue({
+      id: "user_admin",
+      name: "Admin",
+      email: "admin@example.com",
+      totpSecret: null,
+      totpEnabled: false,
+    });
+    const update = vi.fn();
+    const caller = createAdminCaller({
+      user: {
+        findUnique,
+        update,
+      },
+    });
+
+    await expect(caller.verifyAndEnableTotp({ token: "123456" })).rejects.toMatchObject({
+      code: "BAD_REQUEST",
+      message: "No TOTP secret generated. Call generateTotpSecret first.",
+    });
+
+    expect(update).not.toHaveBeenCalled();
+  });
+
+  it("rejects enabling TOTP when it is already active", async () => {
+    const findUnique = vi.fn().mockResolvedValue({
+      id: "user_admin",
+      name: "Admin",
+      email: "admin@example.com",
+      totpSecret: "MOCKSECRET",
+      totpEnabled: true,
+    });
+    const update = vi.fn();
+    const caller = createAdminCaller({
+      user: {
+        findUnique,
+        update,
+      },
+    });
+
+    await expect(caller.verifyAndEnableTotp({ token: "123456" })).rejects.toMatchObject({
+      code: "BAD_REQUEST",
+      message: "TOTP is already enabled.",
+    });
+
+    expect(update).not.toHaveBeenCalled();
+  });
+
+  it("rejects invalid TOTP tokens during self-service enablement", async () => {
+    totpValidateMock.mockReset();
+    totpValidateMock.mockReturnValue(null);
+
+    const findUnique = vi.fn().mockResolvedValue({
+      id: "user_admin",
+      name: "Admin",
+      email: "admin@example.com",
+      totpSecret: "MOCKSECRET",
+      totpEnabled: false,
+    });
+    const update = vi.fn();
+    const caller = createAdminCaller({
+      user: {
+        findUnique,
+        update,
+      },
+    });
+
+    await expect(caller.verifyAndEnableTotp({ token: "123456" })).rejects.toMatchObject({
+      code: "BAD_REQUEST",
+      message: "Invalid TOTP token.",
+    });
+
+    expect(totpValidateMock).toHaveBeenCalledWith({
+      token: "123456",
+      window: 1,
+    });
+    expect(update).not.toHaveBeenCalled();
+  });
+
+  it("enables TOTP for the current user when the token validates", async () => {
+    totpValidateMock.mockReset();
+    totpValidateMock.mockReturnValue(0);
+
+    const findUnique = vi.fn().mockResolvedValue({
+      id: "user_admin",
+      name: "Admin",
+      email: "admin@example.com",
+      totpSecret: "MOCKSECRET",
+      totpEnabled: false,
+    });
+    const update = vi.fn().mockResolvedValue({});
+    const caller = createAdminCaller({
+      user: {
+        findUnique,
+        update,
+      },
+    });
+
+    const result = await caller.verifyAndEnableTotp({ token: "123456" });
+
+    expect(result).toEqual({ enabled: true });
+    expect(update).toHaveBeenCalledWith({
+      where: { id: "user_admin" },
+      data: { totpEnabled: true },
+    });
+  });
+
+  it("verifies login-flow TOTP tokens successfully when enabled", async () => {
+    totpValidateMock.mockReset();
+    totpValidateMock.mockReturnValue(0);
+
+    const findUnique = vi.fn().mockResolvedValue({
+      id: "user_admin",
+      totpSecret: "MOCKSECRET",
+      totpEnabled: true,
+    });
+    const caller = createAdminCaller({
+      user: {
+        findUnique,
+      },
+    });
+
+    const result = await caller.verifyTotp({ userId: "user_admin", token: "123456" });
+
+    expect(result).toEqual({ valid: true });
+    expect(findUnique).toHaveBeenCalledWith({
+      where: { id: "user_admin" },
+      select: { id: true, totpSecret: true, totpEnabled: true },
+    });
+  });
+
+  it("rejects invalid login-flow TOTP tokens with UNAUTHORIZED", async () => {
+    totpValidateMock.mockReset();
+    totpValidateMock.mockReturnValue(null);
+
+    const findUnique = vi.fn().mockResolvedValue({
+      id: "user_admin",
+      totpSecret: "MOCKSECRET",
+      totpEnabled: true,
+    });
+    const caller = createAdminCaller({
+      user: {
+        findUnique,
+      },
+    });
+
+    await expect(caller.verifyTotp({ userId: "user_admin", token: "123456" })).rejects.toMatchObject({
+      code: "UNAUTHORIZED",
+      message: "Invalid TOTP token.",
+    });
+  });
+});
+
+describe("user dashboard and favorites", () => {
+  it("falls back to the normalized default dashboard layout when stored data is invalid", async () => {
+    const findUnique = vi.fn().mockResolvedValue({
+      dashboardLayout: {
+        widgets: [
+          { id: "peakTimes", position: { x: 0, y: 0, w: 4, h: 3 } },
+        ],
+      },
+      updatedAt: new Date("2026-03-30T18:00:00.000Z"),
+    });
+    const caller = createAdminCaller({
+      user: {
+        findUnique,
+      },
+    });
+
+    const result = await caller.getDashboardLayout();
+
+    expect(findUnique).toHaveBeenCalledWith({
+      where: { id: "user_admin" },
+      select: { dashboardLayout: true, updatedAt: true },
+    });
+    expect(result).toEqual({
+      layout: {
+        version: 2,
+        gridCols: 12,
+        widgets: [],
+      },
+      updatedAt: new Date("2026-03-30T18:00:00.000Z"),
+    });
+  });
+
+  it("persists a valid dashboard layout for the current user", async () => {
+    const update = vi.fn().mockResolvedValue({
+      updatedAt: new Date("2026-03-30T19:00:00.000Z"),
+    });
+    const caller = createAdminCaller({
+      user: {
+        update,
+      },
+    });
+
+    const layout = {
+      version: 2,
+      gridCols: 12,
+      widgets: [],
+    };
+
+    const result = await caller.saveDashboardLayout({ layout });
+
+    expect(result).toEqual({
+      updatedAt: new Date("2026-03-30T19:00:00.000Z"),
+    });
+    expect(update).toHaveBeenCalledWith({
+      where: { id: "user_admin" },
+      data: { dashboardLayout: layout },
+      select: { updatedAt: true },
+    });
+  });
+
+  it("persists dashboard layout by db user id even when the session email is stale", async () => {
+    const update = vi.fn().mockResolvedValue({
+      updatedAt: new Date("2026-03-30T19:30:00.000Z"),
+    });
+    const caller = createCaller({
+      session: {
+        user: { email: "stale@example.com", name: "Admin", image: null },
+        expires: "2099-01-01T00:00:00.000Z",
+      },
+      db: {
+        user: {
+          update,
+        },
+      } as never,
+      dbUser: {
+        id: "user_admin",
+        systemRole: SystemRole.ADMIN,
+        permissionOverrides: null,
+      },
+      roleDefaults: null,
+    });
+
+    await caller.saveDashboardLayout({
+      layout: {
+        version: 2,
+        gridCols: 12,
+        widgets: [],
+      },
+    });
+
+    expect(update).toHaveBeenCalledWith({
+      where: { id: "user_admin" },
+      data: {
+        dashboardLayout: {
+          version: 2,
+          gridCols: 12,
+          widgets: [],
+        },
+      },
+      select: { updatedAt: true },
+    });
+  });
+
+  it("returns favorite project ids as an empty list when none are stored", async () => {
+    const findUnique = vi.fn().mockResolvedValue({
+      favoriteProjectIds: null,
+    });
+    const caller = createAdminCaller({
+      user: {
+        findUnique,
+      },
+    });
+
+    const result = await caller.getFavoriteProjectIds();
+
+    expect(result).toEqual([]);
+    expect(findUnique).toHaveBeenCalledWith({
+      where: { id: "user_admin" },
+      select: { favoriteProjectIds: true },
+    });
+  });
+
+  it("adds a project to favorites when it is not already present", async () => {
+    const findUnique = vi.fn().mockResolvedValue({
+      favoriteProjectIds: ["project_1"],
+    });
+    const update = vi.fn().mockResolvedValue({});
+    const caller = createAdminCaller({
+      user: {
+        findUnique,
+        update,
+      },
+    });
+
+    const result = await caller.toggleFavoriteProject({ projectId: "project_2" });
+
+    expect(result).toEqual({
+      favoriteProjectIds: ["project_1", "project_2"],
+      added: true,
+    });
+    expect(update).toHaveBeenCalledWith({
+      where: { id: "user_admin" },
+      data: { favoriteProjectIds: ["project_1", "project_2"] },
+    });
+  });
+
+  it("removes a project from favorites when it is already present", async () => {
+    const findUnique = vi.fn().mockResolvedValue({
+      favoriteProjectIds: ["project_1", "project_2"],
+    });
+    const update = vi.fn().mockResolvedValue({});
+    const caller = createAdminCaller({
+      user: {
+        findUnique,
+        update,
+      },
+    });
+
+    const result = await caller.toggleFavoriteProject({ projectId: "project_2" });
+
+    expect(result).toEqual({
+      favoriteProjectIds: ["project_1"],
+      added: false,
+    });
+    expect(update).toHaveBeenCalledWith({
+      where: { id: "user_admin" },
+      data: { favoriteProjectIds: ["project_1"] },
+    });
+  });
+});
+
+describe("user column preferences and MFA status", () => {
+  it("returns empty column preferences when nothing is stored", async () => {
+    const findUnique = vi.fn().mockResolvedValue({
+      columnPreferences: null,
+    });
+    const caller = createAdminCaller({
+      user: {
+        findUnique,
+      },
+    });
+
+    const result = await caller.getColumnPreferences();
+
+    expect(result).toEqual({});
+    expect(findUnique).toHaveBeenCalledWith({
+      where: { id: "user_admin" },
+      select: { columnPreferences: true },
+    });
+  });
+
+  it("merges column preferences without dropping untouched fields", async () => {
+    const findUnique = vi.fn().mockResolvedValue({
+      columnPreferences: {
+        resources: {
+          visible: ["name", "role"],
+          sort: { field: "name", dir: "asc" },
+          rowOrder: ["name", "role", "email"],
+        },
+      },
+    });
+    const update = vi.fn().mockResolvedValue({ id: "user_admin" });
+    const caller = createAdminCaller({
+      user: {
+        findUnique,
+        update,
+      },
+    });
+
+    const result = await caller.setColumnPreferences({
+      view: "resources",
+      visible: ["name", "email"],
+    });
+
+    expect(result).toEqual({ ok: true });
+    expect(update).toHaveBeenCalledWith({
+      where: { id: "user_admin" },
+      data: {
+        columnPreferences: {
+          resources: {
+            visible: ["name", "email"],
+            sort: { field: "name", dir: "asc" },
+            rowOrder: ["name", "role", "email"],
+          },
+        },
+      },
+    });
+  });
+
+  it("reports the current MFA enabled state", async () => {
+    const findUnique = vi.fn().mockResolvedValue({
+      totpEnabled: true,
+    });
+    const caller = createAdminCaller({
+      user: {
+        findUnique,
+      },
+    });
+
+    const result = await caller.getMfaStatus();
+
+    expect(result).toEqual({ totpEnabled: true });
+    expect(findUnique).toHaveBeenCalledWith({
+      where: { id: "user_admin" },
+      select: { totpEnabled: true },
+    });
+  });
+
+  it("returns NOT_FOUND for MFA status when the current user record no longer exists", async () => {
+    const findUnique = vi.fn().mockResolvedValue(null);
+    const caller = createAdminCaller({
+      user: {
+        findUnique,
+      },
+    });
+
+    await expect(caller.getMfaStatus()).rejects.toMatchObject({
+      code: "NOT_FOUND",
+      message: "User not found",
     });
   });
 });
diff --git a/packages/api/src/router/user.ts b/packages/api/src/router/user.ts
index ac4073d..3bdb6bd 100644
--- a/packages/api/src/router/user.ts
+++ b/packages/api/src/router/user.ts
@@ -57,7 +57,7 @@ export const userRouter = createTRPCRouter({
   me: protectedProcedure.query(async ({ ctx }) => {
     const user = await findUniqueOrThrow(
       ctx.db.user.findUnique({
-        where: { email: ctx.session.user?.email ?? "" },
+        where: { id: ctx.dbUser!.id },
         select: {
           id: true,
           name: true,
@@ -255,24 +255,79 @@ export const userRouter = createTRPCRouter({
       );
 
       if (input.resourceId) {
-        await findUniqueOrThrow(
+        const resource = await findUniqueOrThrow(
           ctx.db.resource.findUnique({
             where: { id: input.resourceId },
-            select: { id: true },
+            select: { id: true, userId: true },
           }),
           "Resource",
         );
 
-        // Unlink any resource previously linked to this user
+        if (resource.userId && resource.userId !== input.userId) {
+          throw new TRPCError({
+            code: "CONFLICT",
+            message: "Resource is already linked to another user",
+          });
+        }
+
+        // Unlink any other resource previously linked to this user.
         await ctx.db.resource.updateMany({
-          where: { userId: input.userId },
+          where: {
+            userId: input.userId,
+            NOT: { id: input.resourceId },
+          },
           data: { userId: null },
         });
-        // Link the new resource
-        await ctx.db.resource.update({
-          where: { id: input.resourceId },
+
+        const linkResult = await ctx.db.resource.updateMany({
+          where: {
+            id: input.resourceId,
+            OR: [
+              { userId: null },
+              { userId: input.userId },
+            ],
+          },
           data: { userId: input.userId },
         });
+
+        if (linkResult.count !== 1) {
+          const [userStillExists, resourceStillExists] = await Promise.all([
+            ctx.db.user.findUnique({
+              where: { id: input.userId },
+              select: { id: true },
+            }),
+            ctx.db.resource.findUnique({
+              where: { id: input.resourceId },
+              select: { id: true, userId: true },
+            }),
+          ]);
+
+          if (!userStillExists) {
+            throw new TRPCError({
+              code: "NOT_FOUND",
+              message: "User not found",
+            });
+          }
+
+          if (!resourceStillExists) {
+            throw new TRPCError({
+              code: "NOT_FOUND",
+              message: "Resource not found",
+            });
+          }
+
+          if (resourceStillExists.userId && resourceStillExists.userId !== input.userId) {
+            throw new TRPCError({
+              code: "CONFLICT",
+              message: "Resource is already linked to another user",
+            });
+          }
+
+          throw new TRPCError({
+            code: "CONFLICT",
+            message: "Resource link changed during update. Please retry.",
+          });
+        }
       } else {
         // Unlink
         await ctx.db.resource.updateMany({
@@ -309,7 +364,7 @@ export const userRouter = createTRPCRouter({
 
   getDashboardLayout: protectedProcedure.query(async ({ ctx }) => {
     const user = await ctx.db.user.findUnique({
-      where: { email: ctx.session.user?.email ?? "" },
+      where: { id: ctx.dbUser!.id },
       select: { dashboardLayout: true, updatedAt: true },
     });
     return {
@@ -322,7 +377,7 @@ export const userRouter = createTRPCRouter({
     .input(z.object({ layout: dashboardLayoutSchema }))
     .mutation(async ({ ctx, input }) => {
       const updated = await ctx.db.user.update({
-        where: { email: ctx.session.user?.email ?? "" },
+        where: { id: ctx.dbUser!.id },
         data: { dashboardLayout: input.layout as unknown as import("@capakraken/db").Prisma.InputJsonValue },
         select: { updatedAt: true },
       });
@@ -531,10 +586,13 @@ export const userRouter = createTRPCRouter({
   verifyAndEnableTotp: protectedProcedure
     .input(z.object({ token: z.string().length(6) }))
     .mutation(async ({ ctx, input }) => {
-      const user = await ctx.db.user.findUniqueOrThrow({
-        where: { id: ctx.dbUser!.id },
-        select: { id: true, name: true, email: true, totpSecret: true, totpEnabled: true },
-      });
+      const user = await findUniqueOrThrow(
+        ctx.db.user.findUnique({
+          where: { id: ctx.dbUser!.id },
+          select: { id: true, name: true, email: true, totpSecret: true, totpEnabled: true },
+        }),
+        "User",
+      );
 
       if (!user.totpSecret) {
         throw new TRPCError({ code: "BAD_REQUEST", message: "No TOTP secret generated. Call generateTotpSecret first." });
@@ -612,10 +670,13 @@ export const userRouter = createTRPCRouter({
   verifyTotp: publicProcedure
     .input(z.object({ userId: z.string(), token: z.string().length(6) }))
     .mutation(async ({ ctx, input }) => {
-      const user = await ctx.db.user.findUniqueOrThrow({
-        where: { id: input.userId },
-        select: { id: true, totpSecret: true, totpEnabled: true },
-      });
+      const user = await findUniqueOrThrow(
+        ctx.db.user.findUnique({
+          where: { id: input.userId },
+          select: { id: true, totpSecret: true, totpEnabled: true },
+        }),
+        "User",
+      );
 
       if (!user.totpEnabled || !user.totpSecret) {
         throw new TRPCError({ code: "BAD_REQUEST", message: "TOTP is not enabled for this user." });
@@ -641,10 +702,13 @@ export const userRouter = createTRPCRouter({
 
   /** Get MFA status for the current user. */
   getMfaStatus: protectedProcedure.query(async ({ ctx }) => {
-    const user = await ctx.db.user.findUniqueOrThrow({
-      where: { id: ctx.dbUser!.id },
-      select: { totpEnabled: true },
-    });
+    const user = await findUniqueOrThrow(
+      ctx.db.user.findUnique({
+        where: { id: ctx.dbUser!.id },
+        select: { totpEnabled: true },
+      }),
+      "User",
+    );
     return { totpEnabled: user.totpEnabled };
   }),
 });