Core fixes:
- Add settingSources to SDK options so CodePilot loads user/project settings
like the CLI (fixes WebFetch timeouts, tool permission issues)
- Delete CLAUDECODE env var to prevent nested session detection when
CodePilot runs alongside Claude Code CLI (fixes 'exited with code 1')
- Remove manual MCP config reading (SDK handles it via settingSources)
- Remove hardcoded timeout env vars (SDK loads from user settings)
UX improvements:
- Remember last selected model across sessions (localStorage)
- Same-project new chat skips directory picker
- File tree auto-refreshes on project switch and after each tool completes
- Left sidebar projects default collapsed (only most recent expanded)
- Right-side file tree defaults collapsed
- Fix file tree icon alignment (spacer size-4 → size-5)
- Dynamic model list from /api/providers/models endpoint
- Provider change dispatches event to refresh model selector
- Improved error messages with provider name and troubleshooting hints
- Fix context button file type matching for extension patterns
- Default tool timeout 120s → 300s