Update client to use /topics endpoint and add getVersion method

- Update listTopics() to use /topics endpoint instead of /
- Add getVersion() method to fetch server version information
- Add VersionResponse type and export it

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

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

src/index.ts

@@ -35,6 +35,7 @@ export type {
   PollOffererResponse,
   PollAnswererResponse,
   PollResponse,
+  VersionResponse,
   HealthResponse,
   ErrorResponse,
   RondevuClientOptions,