feat: add ESLint flat config, Prettier, dependency-cruiser, and Husky

Setup code quality tooling for the monorepo:
- ESLint 9 flat config with TypeScript, import ordering, and NestJS rules
- Prettier with consistent formatting across all files
- dependency-cruiser enforcing module boundary rules (no cross-module internals, no circular deps)
- Husky + lint-staged for pre-commit hooks
- Auto-fixed existing files for type imports and import ordering

Co-Authored-By: Paperclip <noreply@paperclip.ing>

package.json

@@ -8,17 +8,58 @@
   "pnpm": {
     "onlyBuiltDependencies": [
       "@nestjs/core",
-      "esbuild"
+      "@prisma/client",
+      "@prisma/engines",
+      "esbuild",
+      "prisma"
     ]
   },
   "scripts": {
     "dev": "turbo run dev",
     "build": "turbo run build",
-    "lint": "turbo run lint",
+    "lint": "eslint .",
     "test": "turbo run test",
-    "typecheck": "turbo run typecheck"
+    "typecheck": "turbo run typecheck",
+    "format": "prettier --write .",
+    "format:check": "prettier --check .",
+    "dep-cruise": "depcruise src/ apps/ --config .dependency-cruiser.cjs",
+    "db:generate": "prisma generate",
+    "db:migrate:dev": "prisma migrate dev",
+    "db:migrate:deploy": "prisma migrate deploy",
+    "db:seed": "prisma db seed",
+    "db:studio": "prisma studio",
+    "db:reset": "prisma migrate reset",
+    "prepare": "husky"
+  },
+  "lint-staged": {
+    "*.{ts,tsx}": [
+      "eslint --fix",
+      "prettier --write"
+    ],
+    "*.{json,md,yaml,yml}": [
+      "prettier --write"
+    ]
+  },
+  "prisma": {
+    "seed": "tsx prisma/seed.ts"
   },
   "devDependencies": {
-    "turbo": "^2.9.4"
+    "@eslint/js": "^9.39.4",
+    "dependency-cruiser": "^17.3.10",
+    "eslint": "^9.39.4",
+    "eslint-config-prettier": "^10.1.8",
+    "eslint-import-resolver-typescript": "^4.4.4",
+    "eslint-plugin-import-x": "^4.16.2",
+    "globals": "^17.4.0",
+    "husky": "^9.1.7",
+    "lint-staged": "^16.4.0",
+    "prettier": "^3.8.1",
+    "prisma": "^6.19.3",
+    "tsx": "^4.21.0",
+    "turbo": "^2.9.4",
+    "typescript-eslint": "^8.58.0"
+  },
+  "dependencies": {
+    "@prisma/client": "^6.19.3"
   }
 }