feat: Implement content-based offer IDs with SHA-256 hashing

- Added hash-id.ts utility for SHA-256 content hashing
- Offer IDs now generated from hash of {sdp, topics} (sorted)
- Removed peerId from hash (inferred from authentication)
- Server generates deterministic IDs for idempotent offer creation
- Updated SQLite and D1 storage implementations
- Removed optional id field from CreateOfferRequest
- Same offer content always produces same ID

🤖 Generated with [Claude Code](https://claude.com/claude-code)

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

src/index.ts

@@ -0,0 +1,75 @@
+import { serve } from '@hono/node-server';
+import { createApp } from './app.ts';
+import { loadConfig } from './config.ts';
+import { SQLiteStorage } from './storage/sqlite.ts';
+import { Storage } from './storage/types.ts';
+
+/**
+ * Main entry point for the standalone Node.js server
+ */
+async function main() {
+  const config = loadConfig();
+
+  console.log('Starting Rondevu server...');
+  console.log('Configuration:', {
+    port: config.port,
+    storageType: config.storageType,
+    storagePath: config.storagePath,
+    offerDefaultTtl: `${config.offerDefaultTtl}ms`,
+    offerMaxTtl: `${config.offerMaxTtl}ms`,
+    offerMinTtl: `${config.offerMinTtl}ms`,
+    cleanupInterval: `${config.cleanupInterval}ms`,
+    maxOffersPerRequest: config.maxOffersPerRequest,
+    maxTopicsPerOffer: config.maxTopicsPerOffer,
+    corsOrigins: config.corsOrigins,
+    version: config.version,
+  });
+
+  let storage: Storage;
+
+  if (config.storageType === 'sqlite') {
+    storage = new SQLiteStorage(config.storagePath);
+    console.log('Using SQLite storage');
+  } else {
+    throw new Error('Unsupported storage type');
+  }
+
+  // Start periodic cleanup of expired offers
+  const cleanupInterval = setInterval(async () => {
+    try {
+      const now = Date.now();
+      const deleted = await storage.deleteExpiredOffers(now);
+      if (deleted > 0) {
+        console.log(`Cleanup: Deleted ${deleted} expired offer(s)`);
+      }
+    } catch (err) {
+      console.error('Cleanup error:', err);
+    }
+  }, config.cleanupInterval);
+
+  const app = createApp(storage, config);
+
+  const server = serve({
+    fetch: app.fetch,
+    port: config.port,
+  });
+
+  console.log(`Server running on http://localhost:${config.port}`);
+  console.log('Ready to accept connections');
+
+  // Graceful shutdown handler
+  const shutdown = async () => {
+    console.log('\nShutting down gracefully...');
+    clearInterval(cleanupInterval);
+    await storage.close();
+    process.exit(0);
+  };
+
+  process.on('SIGINT', shutdown);
+  process.on('SIGTERM', shutdown);
+}
+
+main().catch((err) => {
+  console.error('Fatal error:', err);
+  process.exit(1);
+});