Add Drizzle + Postgres setup (task 03)

drizzle-orm + postgres driver + drizzle-kit wired up. Core schema declares
users, households, and household_members. docker-compose.dev.yaml runs
Postgres 16 locally. Initial migration generated and verified applied.

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

package.json

@@ -15,7 +15,10 @@
     "lint:fix": "eslint . --fix",
     "format": "prettier --write .",
     "format:check": "prettier --check .",
-    "typecheck": "tsc --noEmit"
+    "typecheck": "tsc --noEmit",
+    "db:generate": "drizzle-kit generate",
+    "db:migrate": "drizzle-kit migrate",
+    "db:studio": "drizzle-kit studio"
   },
   "devDependencies": {
     "@eslint/eslintrc": "^3.3.5",
@@ -24,6 +27,7 @@
     "@types/node": "^22.9.0",
     "@types/react": "^19.2.14",
     "@types/react-dom": "^19.2.3",
+    "drizzle-kit": "^0.31.10",
     "eslint": "^9.15.0",
     "eslint-config-next": "^16.2.4",
     "globals": "^15.12.0",
@@ -36,8 +40,10 @@
     "@base-ui/react": "^1.4.1",
     "class-variance-authority": "^0.7.1",
     "clsx": "^2.1.1",
+    "drizzle-orm": "^0.45.2",
     "lucide-react": "^1.14.0",
     "next": "^15.5.15",
+    "postgres": "^3.4.9",
     "react": "^19.2.5",
     "react-dom": "^19.2.5",
     "shadcn": "^4.7.0",