Remote control fails with 400 'title: maximum string length is 500' for sessions with long compaction-summary titles

Bug

Toggling Remote control in the VS Code extension fails permanently for sessions whose title exceeds the server limit. The client sends the session title untruncated and the API rejects it, so remote control can never connect for that session.

Evidence (extension log)

[code-session] Session create failed 400: title: maximum string length is 500
[remote-bridge] createCodeSession failed (attempt 1/3), retrying in 386ms
[code-session] Session create failed 400: title: maximum string length is 500
[remote-bridge] createCodeSession failed (attempt 2/3), retrying in 1225ms
[bridge:sdk] State change: failed - Session creation failed - see debug log

All 3 retries fail with the same 400 (retrying a validation error can never succeed).

Repro

1. Have a long-running session that was resumed/continued from compaction (its title/first message is a large auto-generated summary, far over 500 chars).
2. Toggle Remote control in the VS Code extension.
3. createCodeSession returns 400 title: maximum string length is 500; bridge state = failed.

Expected

Client truncates the title to 500 chars or less before calling createCodeSession (or the server truncates instead of rejecting). A 400 validation error should also not be retried.

Environment

• Claude Code VS Code extension, Windows 11 Pro 10.0.26200
• OAuth authenticated (log shows OAuth tokens found in secure storage); all MCP servers connect normally