Make debugger control commands non-blocking

[ksa-real]

Summary

• return promptly after VS Code accepts start, continue, restart, and step commands
• support optional bounded timeoutMs waits and add explicit wait_for_debug_stop
• report resolved launch configuration, session identity, state, and stopped details
• document the revised MCP tool contract and remove polling-based synchronization
• verify standard MCP ping and propagation of request cancellation signals

Tests

• npm run compile
• npm run lint
• npm test — 71 passing

This is a stacked PR based on feat/mcp-auth-token.