refactor: full DDD + Clean Architecture refactor

- Hapus src/utils/ (17 files) + src/db/ (8 files) dead code
- Absorb 7 re-export stubs → real impl di lokasi DDD
- Buat src/infrastructure/di.ts (DI container)
- Rewrite 5 controllers pakai repository/DI
- Fix shared/utils imports, env.ts, routes, index.ts
- Update package.json build path migrate
- Lint clean, build clean

src/interfaces/s3/headers.ts

@@ -1,10 +1,52 @@
-/**
- * Re-export from the canonical headers implementation.
- *
- * @module
- */
-export {
-  applyS3Headers,
-  S3_CORS_HEADERS,
-  s3Headers,
-} from '../../utils/s3/headers';
+import { nanoid } from 'nanoid';
+
+export const S3_CORS_HEADERS: Record<string, string> = {
+  'access-control-allow-origin': '*',
+  'access-control-allow-methods': 'GET, PUT, HEAD, DELETE, POST, OPTIONS',
+  'access-control-allow-headers': [
+    'Authorization',
+    'Content-Type',
+    'Content-MD5',
+    'Range',
+    'If-Match',
+    'If-None-Match',
+    'If-Modified-Since',
+    'If-Unmodified-Since',
+    'X-Amz-*',
+    'x-amz-*',
+  ].join(', '),
+  'access-control-expose-headers': [
+    'Accept-Ranges',
+    'Content-Length',
+    'Content-Range',
+    'Content-Type',
+    'ETag',
+    'Last-Modified',
+    'x-amz-id-2',
+    'x-amz-request-id',
+  ].join(', '),
+  'access-control-max-age': '86400',
+};
+
+export const s3Headers = (
+  requestId: string,
+  extraHeaders: Record<string, string> = {},
+): Record<string, string> => ({
+  ...S3_CORS_HEADERS,
+  server: 'AmazonS3',
+  ...(requestId
+    ? {
+        'x-amz-request-id': requestId,
+        'x-amz-id-2': `${requestId}+${nanoid(16)}`,
+      }
+    : {}),
+  ...extraHeaders,
+});
+
+export const applyS3Headers = (headers: Headers, requestId: string): Headers => {
+  const result = new Headers(headers);
+  for (const [key, value] of Object.entries(s3Headers(requestId))) {
+    result.set(key, value);
+  }
+  return result;
+};