feat: LiveKit video grid improvements, voice state cleanup, and internal tooling

- Video grid: sync stream type attribute on updates, add screenshare data attribute
- Dispatcher: handle voice_token messages, improve video track event handling
- LiveKit session: add video track publication support
- Hub: stale client timeout cleanup, improved voice state management
- Voice join/leave: context propagation, better error handling
- Livekit webhook: structured event handling with room/participant data
- Server DB: voice query improvements, new test coverage
- WS integration tests: expanded coverage for voice and LiveKit flows
- Gitignore: add internal dev tools directory, owncord-server.exe

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

.gitignore

@@ -19,6 +19,7 @@ skills/
 # Server runtime artifacts
 Server/chatserver.exe
 Server/chatserver.exe~
+Server/owncord-server.exe
 Server/config.yaml
 Server/data/
 
@@ -48,6 +49,9 @@ node_modules/
 .mcp.json
 .superpowers/
 
+# Internal dev tools
+tools/
+
 # Internal dev files
 SKILL.md
 TODOS.md