feat: add server entry point

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

src/server.js

@@ -0,0 +1,20 @@
+import { loadConfig } from './config.js';
+import { getPool } from './db.js';
+import { ensureStorageDirs } from './storage.js';
+import { createApp } from './app.js';
+
+async function main() {
+  const config = loadConfig();
+  await ensureStorageDirs(config);
+  const pool = getPool(config);
+  const app = createApp(config, pool);
+
+  app.listen(config.port, () => {
+    console.log(`File converter API listening on port ${config.port}`);
+  });
+}
+
+main().catch((error) => {
+  console.error('Failed to start server:', error);
+  process.exit(1);
+});