feat: SMTP full ENV override, password reset flow, and E2E email testing

- SMTP: SMTP_HOST/PORT/USER/FROM/TLS now all have ENV override support
  (previously only SMTP_PASSWORD was env-aware). ENV takes priority over DB.
- docker-compose.yml: forward all SMTP_* env vars to app container + add
  Mailhog service (ports 1025 SMTP / 8025 HTTP, always available in dev)
- Password reset: PasswordResetToken Prisma model + authRouter with
  requestPasswordReset (timing-safe, no email enumeration) + resetPassword
- UI: /auth/forgot-password, /auth/reset-password/[token] pages +
  "Forgot password?" link on sign-in page
- E2E: Mailhog helpers (getLatestEmailTo, clearMailhog, extractUrlFromEmail)
  + invite-flow.spec.ts + password-reset.spec.ts

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

packages/api/src/router/auth.ts

@@ -0,0 +1,101 @@
+import { randomBytes } from "node:crypto";
+import { TRPCError } from "@trpc/server";
+import { z } from "zod";
+import { createTRPCRouter, publicProcedure } from "../trpc.js";
+import { sendEmail } from "../lib/email.js";
+
+const RESET_TTL_MS = 60 * 60 * 1000; // 1 hour
+
+function resetEmailHtml(resetUrl: string): string {
+  return `
+    <p>You requested a password reset for your CapaKraken account.</p>
+    <p>Click the link below to set a new password:</p>
+    <p><a href="${resetUrl}">${resetUrl}</a></p>
+    <p>This link expires in 1 hour and can only be used once.</p>
+    <p>If you did not request this, you can ignore this email.</p>
+  `;
+}
+
+export const authRouter = createTRPCRouter({
+  /**
+   * Request a password reset email.
+   * Always returns { success: true } — even if the email is not registered —
+   * to prevent user enumeration.
+   */
+  requestPasswordReset: publicProcedure
+    .input(z.object({ email: z.string().email() }))
+    .mutation(async ({ ctx, input }) => {
+      const user = await ctx.db.user.findUnique({
+        where: { email: input.email },
+        select: { id: true, email: true },
+      });
+
+      if (!user) {
+        // Timing-safe: don't reveal whether the email exists
+        return { success: true };
+      }
+
+      // Delete any existing (unused) reset tokens for this email
+      await ctx.db.passwordResetToken.deleteMany({
+        where: { email: input.email, usedAt: null },
+      });
+
+      const token = randomBytes(32).toString("hex");
+      const expiresAt = new Date(Date.now() + RESET_TTL_MS);
+
+      await ctx.db.passwordResetToken.create({
+        data: { email: input.email, token, expiresAt },
+      });
+
+      const baseUrl = process.env["NEXTAUTH_URL"] ?? "http://localhost:3100";
+      const resetUrl = `${baseUrl}/auth/reset-password/${token}`;
+
+      void sendEmail({
+        to: input.email,
+        subject: "CapaKraken — reset your password",
+        text: `You requested a password reset.\n\nReset your password: ${resetUrl}\n\nThis link expires in 1 hour. If you did not request this, ignore this email.`,
+        html: resetEmailHtml(resetUrl),
+      });
+
+      return { success: true };
+    }),
+
+  /** Validate a reset token and set a new password. */
+  resetPassword: publicProcedure
+    .input(
+      z.object({
+        token: z.string().min(1),
+        password: z.string().min(8, "Password must be at least 8 characters."),
+      }),
+    )
+    .mutation(async ({ ctx, input }) => {
+      const record = await ctx.db.passwordResetToken.findUnique({
+        where: { token: input.token },
+      });
+
+      if (!record) {
+        throw new TRPCError({ code: "NOT_FOUND", message: "Reset link not found." });
+      }
+      if (record.usedAt) {
+        throw new TRPCError({ code: "BAD_REQUEST", message: "This reset link has already been used." });
+      }
+      if (record.expiresAt < new Date()) {
+        throw new TRPCError({ code: "BAD_REQUEST", message: "This reset link has expired." });
+      }
+
+      const { hash } = await import("@node-rs/argon2");
+      const passwordHash = await hash(input.password);
+
+      await ctx.db.user.update({
+        where: { email: record.email },
+        data: { passwordHash },
+      });
+
+      await ctx.db.passwordResetToken.update({
+        where: { token: input.token },
+        data: { usedAt: new Date() },
+      });
+
+      return { success: true };
+    }),
+});