chore: monorepo 工作区与开发环境

Bun workspaces + 根 tsconfig、开发用 PostgreSQL compose、.env.example（端口 18456、SK_KEY_ENCRYPTION_SECRET 等）。

tsconfig.json

@@ -0,0 +1,31 @@
+{
+  "compilerOptions": {
+    "lib": ["ESNext", "DOM", "DOM.Iterable"],
+    "types": ["bun"],
+    "target": "ESNext",
+    "module": "Preserve",
+    "moduleDetection": "force",
+    "moduleResolution": "bundler",
+    "allowImportingTsExtensions": true,
+    "verbatimModuleSyntax": true,
+    "noEmit": true,
+    "strict": true,
+    "skipLibCheck": true,
+    "isolatedModules": true,
+    "esModuleInterop": true,
+    "forceConsistentCasingInFileNames": true,
+    "resolveJsonModule": true,
+    "noUncheckedIndexedAccess": true,
+    "paths": {
+      "@new-api-key-usage/core": ["./packages/core/src/index.ts"],
+      "@new-api-key-usage/db": ["./packages/db/src/index.ts"]
+    }
+  },
+  "include": [
+    "apps/server/src/**/*.ts",
+    "apps/server/test/**/*.ts",
+    "packages/*/src/**/*.ts",
+    "packages/*/test/**/*.ts",
+    "packages/*/drizzle.config.ts"
+  ]
+}