Replace direct file overwriting with a staging-based update mechanism to
resolve "file in use" errors during self-updates.
**Changes:**
- Stage updates to temporary directory instead of direct installation
- Apply staged updates on next application startup (before files are loaded)
- Add static methods for startup update detection and application
- Create update manifest to track staged update metadata
- Backup existing files before applying updates
- Update UI messaging to reflect staged update workflow
**Problem solved:**
The previous direct file replacement approach failed when trying to overwrite
DLLs and executables that were loaded into memory by the running process.
This two-stage approach stages files safely, then applies them on restart
when no files are in use.
**Workflow:**
1. Download and extract update to staging directory
2. Create manifest with update metadata
3. Show "Update ready" message to user
4. On next app startup: detect staged update, apply it, show success message
5. Clean up staging directory after successful application
This ensures reliable self-updates without file access conflicts.
Signed-off-by: Zephyron <zephyron@citron-emu.org>
Implement a complete auto-updater system for Citron with the following features:
- Add UpdaterService class for handling update checks, downloads, and installations
- Add UpdaterDialog with progress tracking and user interaction
- Support both .zip and .7z archives with Windows PowerShell fallback
- Automatic background update checking on startup (3-second delay)
- Silent notifications when updates are available
- Manual "Check for Updates" menu option in Help menu
- User setting to enable/disable automatic update checks (enabled by default)
- Graceful error handling with detailed logging
- Restart functionality after successful updates
- Libarchive integration for cross-platform archive support
The system uses HTTP URLs to bypass SSL library compatibility issues and
provides a smooth user experience with minimal interruption during automatic
checks. Manual updates show a full dialog with progress tracking and changelog
information.
Fixes update distribution workflow and keeps users informed of new releases.
Signed-off-by: Zephyron <zephyron@citron-emu.org>
