feat(db+auth): add pg pool, admin_users email/provider migration, refactor auth lookup

- Create src/lib/db.ts (shared pg.Pool, query/withTx helpers, server-only)
- Add @types/pg devDep
- Migration 204: add email, auth_provider, auth_subject columns to
  admin_users; backfill from auth.users; new upsert_admin_user accepts
  multi-provider args; new get_admin_user_for_session RPC resolves
  Auth.js session id (UUID or Google sub) to an admin row
- Refactor getAdminUser() to use pg + new RPC; auto-provisions on first
  Google sign-in using session.user.email
- Refactor updatePasswordAction to call update_user_password via pg
  (drops the Supabase REST hop)
- Delete orphaned src/actions/login.ts (replaced by auth-actions.ts)
- Drop remaining DEV_FORCE_UID references in users.ts; dev path now
  uses dev_session cookie (the only cookie the dev flow can set)
- Update AdminUser type: user_id is now string | null (Google users
  have no Supabase auth id); add email + auth_provider fields
- Fix downstream type errors: StopProductAssignment.callerUid accepts
  null; pickup.ts performedBy widens to string | null
- Bump vitest config, tests/, and other earlier cleanup changes

package.json

@@ -11,11 +11,15 @@
     "migrate": "node supabase/push-migrations.js",
     "migrate:one": "node supabase/push-migrations.js",
     "type-check": "npx tsc --noEmit",
+    "test": "vitest run",
+    "test:watch": "vitest",
+    "test:ui": "vitest --ui",
+    "test:e2e": "playwright test --project=local",
+    "test:e2e:prod": "PLAYWRIGHT_PROD=1 playwright test",
     "format": "prettier --write \"src/**/*.{ts,tsx}\""
   },
   "dependencies": {
     "@anthropic-ai/sdk": "^0.96.0",
-    "@clerk/nextjs": "^7.4.2",
     "@google/generative-ai": "^0.24.1",
     "@gsap/react": "^2.1.2",
     "@sentry/nextjs": "^10.55.0",
@@ -28,6 +32,7 @@
     "gsap": "^3.15.0",
     "lucide-react": "^1.17.0",
     "next": "^16.2.6",
+    "next-auth": "^5.0.0-beta.31",
     "next-themes": "^0.4.6",
     "openai": "^6.37.0",
     "papaparse": "^5.5.3",
@@ -48,17 +53,22 @@
     "@tailwindcss/postcss": "^4",
     "@types/node": "^20",
     "@types/papaparse": "^5.5.2",
+    "@types/pg": "^8.20.0",
     "@types/qrcode": "^1.5.6",
     "@types/react": "^19",
     "@types/react-dom": "^19",
     "@types/uuid": "^11.0.0",
+    "@vitejs/plugin-react": "^4.7.0",
     "dotenv": "^17.4.2",
     "eslint": "^9",
     "eslint-config-next": "16.2.5",
+    "jsdom": "^25.0.1",
     "pg": "^8.20.0",
     "playwright": "^1.59.1",
     "tailwindcss": "^4",
-    "typescript": "^5"
+    "typescript": "^5",
+    "vite-tsconfig-paths": "^5.1.4",
+    "vitest": "^2.1.9"
   },
   "overrides": "{}"
 }