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>

package.json

@@ -0,0 +1,27 @@
+{
+  "name": "@xtr-dev/rondevu-server",
+  "version": "0.1.0",
+  "description": "Topic-based peer discovery and signaling server for distributed P2P applications",
+  "main": "dist/index.js",
+  "scripts": {
+    "build": "node build.js",
+    "typecheck": "tsc",
+    "dev": "ts-node src/index.ts",
+    "start": "node dist/index.js",
+    "test": "echo \"Error: no test specified\" && exit 1",
+    "deploy": "npx wrangler deploy src/worker.ts --var VERSION:$(git rev-parse --short HEAD)"
+  },
+  "devDependencies": {
+    "@cloudflare/workers-types": "^4.20251014.0",
+    "@types/better-sqlite3": "^7.6.13",
+    "@types/node": "^24.9.2",
+    "esbuild": "^0.25.11",
+    "ts-node": "^10.9.2",
+    "typescript": "^5.9.3"
+  },
+  "dependencies": {
+    "@hono/node-server": "^1.19.6",
+    "better-sqlite3": "^12.4.1",
+    "hono": "^4.10.4"
+  }
+}