v0.65.0: Diagnostics command, GitHub comments in diff viewer, and Mission Mode fixes

New features

- /diagnostics command - New /diagnostics command with overlay menu and footer status for troubleshooting CLI issues
- Unstaged changes in diff viewer - View and manage unstaged changes directly in the diff viewer panel (Factory App)
- GitHub comments in diff viewer - View GitHub PR comments alongside code changes in the diff viewer (Factory App)
- Session deep linking - Share and navigate directly to specific sessions via deep links (Factory App)
- Diff preview for enterprise controls - Preview configuration diffs when managing enterprise control settings (Factory App)

Bug fixes

- Mission Mode model selection - Fixed model selection issues when using Mission Mode
- Mission Mode validation - Validation contracts now update correctly when Mission requirements change
- Bug report smart trimming - Bug reports now smart-trim large files instead of failing
- Plugin auto-install - Fixed duplicate core plugin auto-install failures being surfaced to users