db: drizzle schema matching spec 02, initial migrations, settings service

Migration 0000 enables citext; 0001 creates all 39 tables. DB tests use a
throwaway database per file (TEST_DATABASE_URL, derived from .env in dev,
a postgres service in CI). Decision 0002: pg driver and @fastify/cookie.

Task: M1-T1

apps/api/package.json

@@ -7,12 +7,19 @@
   "scripts": {
     "dev": "node --watch --env-file-if-exists=../../.env --conditions=source src/index.ts",
     "build": "tsc -p tsconfig.build.json",
-    "typecheck": "tsc --noEmit"
+    "typecheck": "tsc --noEmit",
+    "db:generate": "drizzle-kit generate"
   },
   "dependencies": {
     "@fastify/static": "^10.1.6",
     "@selfphoneng/shared": "workspace:*",
+    "drizzle-orm": "^0.45.4",
     "fastify": "^5.12.7",
+    "pg": "^8.23.1",
     "zod": "^4.6.7"
+  },
+  "devDependencies": {
+    "@types/pg": "^8.23.1",
+    "drizzle-kit": "^0.31.11"
   }
 }