feat(auth): phase 3 — replace Supabase GoTrue with bcryptjs+jose

Custom auth stack: bcryptjs password hashing (cost 10, GoTrue-compatible),
jose JWT session cookies (edge-safe, 8hr TTL), new API routes for
login/logout/reset/change-password, middleware rewritten to JWT-only
verification with no DB access. All 38 protected pages and API routes
migrated from supabase.auth.getUser() to getSession(). Supabase .from()
queries retained for Phase 4. lib/db/index.ts refactored to lazy Proxy
singleton to avoid module-level throw during Next.js build.

tsc: clean, build: clean, tests: 4/4 passed

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

app/api/auth/login/route.ts

@@ -0,0 +1,61 @@
+export const dynamic = 'force-dynamic'
+
+import { NextRequest, NextResponse } from 'next/server'
+import { asAdmin } from '@/lib/db/with-user'
+import { users } from '@/lib/db/schema'
+import { eq } from 'drizzle-orm'
+import { verifyPassword } from '@/lib/auth/password'
+import { createSession } from '@/lib/auth/session'
+
+export async function POST(req: NextRequest) {
+  const { email, password } = await req.json()
+  if (!email || !password) {
+    return NextResponse.json({ error: 'Email and password required' }, { status: 400 })
+  }
+
+  const [user] = await asAdmin(db =>
+    db.select({
+      id: users.id,
+      email: users.email,
+      name: users.name,
+      role: users.role,
+      siteId: users.siteId,
+      passwordHash: users.passwordHash,
+      active: users.active,
+    }).from(users).where(eq(users.email, email.toLowerCase())).limit(1)
+  )
+
+  if (!user || !user.active) {
+    return NextResponse.json({ error: 'Invalid credentials' }, { status: 401 })
+  }
+
+  if (!user.passwordHash) {
+    return NextResponse.json({ error: 'Account not configured — contact admin' }, { status: 401 })
+  }
+
+  const valid = await verifyPassword(password, user.passwordHash)
+  if (!valid) {
+    return NextResponse.json({ error: 'Invalid credentials' }, { status: 401 })
+  }
+
+  // Update last_login_at
+  await asAdmin(db => db.update(users).set({ lastLoginAt: new Date() }).where(eq(users.id, user.id)))
+
+  const token = await createSession({
+    sub: user.id,
+    role: user.role,
+    siteId: user.siteId ?? null,
+    name: user.name,
+  })
+
+  const appUrl = process.env.APP_URL ?? ''
+  const res = NextResponse.json({ ok: true })
+  res.cookies.set('ims_session', token, {
+    httpOnly: true,
+    secure: appUrl.startsWith('https'),
+    sameSite: 'lax',
+    maxAge: 8 * 60 * 60,
+    path: '/',
+  })
+  return res
+}