Add topics endpoint and refactor to topic-based discovery

- Add GET /topics endpoint with pagination and peer counts
- Refactor offers to support multiple topics per offer
- Add stateless authentication with AES-256-GCM
- Add bloom filter support for peer exclusion
- Update database schema for topic-based discovery
- Add comprehensive API documentation to README

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

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

package.json

@@ -1,7 +1,7 @@
 {
   "name": "@xtr-dev/rondevu-server",
-  "version": "0.0.1",
-  "description": "Open signaling and tracking server for peer discovery in distributed P2P applications",
+  "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",