feat: Sprint 1 — staffing assign, dashboard cache, bulk ops, notifications

Staffing "Assign" Button:
- Inline assignment form on each suggestion card in StaffingPanel
- Pre-fills project, dates, hours from search criteria
- 1-click confirm creates allocation with PROPOSED status
- Success/error toasts, removes assigned suggestions from list

Dashboard Redis Caching:
- New cache utility (packages/api/src/lib/cache.ts) with get/set/invalidate
- All 5 dashboard queries wrapped with 60s TTL cache-aside pattern
- Auto-invalidation on allocation + project mutations (fire-and-forget)
- Graceful fallthrough to DB if Redis unavailable

Bulk Operations:
- CSV export for selected resources and projects (apps/web/src/lib/csv-export.ts)
- Project batch delete mutation with cascade (assignments, demands, rules)
- Export/Delete buttons added to BatchActionBar on both list pages

Budget Overrun Notifications:
- checkBudgetThresholds() alerts at 80% (HIGH) and 100% (URGENT)
- Called after every allocation mutation, duplicate-safe
- Targets ADMIN + MANAGER users with SSE delivery

Estimate Approval Reminders:
- checkPendingEstimateReminders() finds SUBMITTED versions > 3 days old
- Cron endpoint: GET /api/cron/estimate-reminders (optional CRON_SECRET auth)
- Creates in-app REMINDER notifications, duplicate-safe

Co-Authored-By: claude-flow <ruv@ruv.net>

packages/api/src/router/project.ts

@@ -12,6 +12,7 @@ import { buildDynamicFieldWhereClauses } from "./custom-field-filters.js";
 import { loadProjectPlanningReadModel } from "./project-planning-read-model.js";
 import { adminProcedure, controllerProcedure, createTRPCRouter, managerProcedure, protectedProcedure, requirePermission } from "../trpc.js";
 import { createDalleClient, isDalleConfigured, parseAiError } from "../ai-client.js";
+import { invalidateDashboardCache } from "../lib/cache.js";
 
 const MAX_COVER_SIZE = 4 * 1024 * 1024; // 4 MB base64 string length limit (client compresses before upload)
 
@@ -155,6 +156,7 @@ export const projectRouter = createTRPCRouter({
         },
       });
 
+      void invalidateDashboardCache();
       return project;
     }),
 
@@ -207,6 +209,7 @@ export const projectRouter = createTRPCRouter({
         },
       });
 
+      void invalidateDashboardCache();
       return updated;
     }),
 
@@ -214,10 +217,12 @@ export const projectRouter = createTRPCRouter({
     .input(z.object({ id: z.string(), status: z.nativeEnum(ProjectStatus) }))
     .mutation(async ({ ctx, input }) => {
       requirePermission(ctx, PermissionKey.MANAGE_PROJECTS);
-      return ctx.db.project.update({
+      const result = await ctx.db.project.update({
         where: { id: input.id },
         data: { status: input.status },
       });
+      void invalidateDashboardCache();
+      return result;
     }),
 
   batchUpdateStatus: managerProcedure
@@ -244,6 +249,7 @@ export const projectRouter = createTRPCRouter({
         },
       });
 
+      void invalidateDashboardCache();
       return { count: updated.length };
     }),
 
@@ -349,9 +355,50 @@ export const projectRouter = createTRPCRouter({
         });
       });
 
+      void invalidateDashboardCache();
       return { id: input.id, name: project.name };
     }),
 
+  batchDelete: adminProcedure
+    .input(
+      z.object({
+        ids: z.array(z.string()).min(1).max(50),
+      }),
+    )
+    .mutation(async ({ ctx, input }) => {
+      const projects = await ctx.db.project.findMany({
+        where: { id: { in: input.ids } },
+        select: { id: true, name: true, shortCode: true },
+      });
+
+      if (projects.length === 0) {
+        throw new TRPCError({ code: "NOT_FOUND", message: "No projects found" });
+      }
+
+      await ctx.db.$transaction(async (tx) => {
+        const ids = projects.map((p) => p.id);
+        await tx.assignment.deleteMany({ where: { projectId: { in: ids } } });
+        await tx.demandRequirement.deleteMany({ where: { projectId: { in: ids } } });
+        await tx.calculationRule.updateMany({
+          where: { projectId: { in: ids } },
+          data: { projectId: null },
+        });
+        await tx.project.deleteMany({ where: { id: { in: ids } } });
+        await tx.auditLog.create({
+          data: {
+            entityType: "Project",
+            entityId: ids.join(","),
+            action: "DELETE",
+            ...(ctx.dbUser?.id ? { userId: ctx.dbUser.id } : {}),
+            changes: { before: projects } as never,
+          },
+        });
+      });
+
+      void invalidateDashboardCache();
+      return { count: projects.length };
+    }),
+
   // ─── Cover Art ──────────────────────────────────────────────────────────────
 
   generateCover: managerProcedure