* feat: add /undo, /redo, /timeline slash commands and fork button
- Add /undo command to revert to previous user message
- Add /redo command to redo previously undone messages
- Add /timeline command to show conversation history
- Add fork button on user messages (hover) to create new session
- Add TimelineDialog component for navigating conversation history
- Show undo/redo/timeline in autocomplete when session exists
- Fix fork to use SDK session.fork API
- Silent no-op behavior for undo/redo when no messages (matches OpenCode CLI)
* fix: correct fork session endpoint and session switching
- Add hybrid SDK approach using v1 for existing methods and v2 for fork only
- v2 SDK has correct endpoint /session/{sessionID}/fork instead of broken /session/{id}/fork
- Fix forkFromMessage to use setCurrentSession instead of direct set
- Ensures both useSessionStore and useSessionManagementStore are consistent
- Fixes issue where forked sessions appeared empty until sending a new message
* fix: use direct fetch for fork to avoid v2 SDK build errors
- Remove v2 SDK imports and hybrid SDK approach
- Use direct fetch() call to /api/session/{sessionID}/fork endpoint
- Avoids type conflicts between v1 and v2 SDK
- Bypasses broken v1 SDK fork endpoint (wrong path parameter)
- All codebase now uses v1 SDK consistently
* fix: use jsonc-parser for config file parsing
- Replace strip-json-comments + JSON.parse with jsonc-parser
- Handles comments, trailing commas, and unquoted keys
- Matches OpenCode CLI config parsing behavior
- Fixes SyntaxError when reading global opencode.json config
* feat: improve timeline dialog with loading state and search
- Add loading spinner on fork button during operation (~30s on big sessions)
- Refresh session list after fork so new session appears in sidebar immediately
- Add search bar to filter messages by prompt text content
- Show 'No messages found' when search has no results
- Disable fork button while forking to prevent duplicate operations