Implements video transformation features:
- Horizontal flip (mirror effect) using hflip filter
- Vertical flip (upside down) using vflip filter
- Rotation support: 90°, 180°, 270° clockwise using transpose filters
UI additions in Advanced mode:
- New "VIDEO TRANSFORMATIONS" section
- Two checkboxes for flip controls with descriptive labels
- Dropdown selector for rotation angles
- Hint text explaining transformation purpose
Filter implementation:
- Applied after aspect ratio conversion, before frame rate conversion
- Works in both queue-based and direct conversion paths
- Uses FFmpeg standard filters: hflip, vflip, transpose
Addresses user request to add flip/rotation capabilities inspired by Jake's script using -vf hflip.
This commit includes three critical bug fixes and Windows build improvements:
**Bug Fixes:**
1. **Queue Conversion Progress Tracking** (main.go:1471-1534)
- Enhanced executeConvertJob() to parse FPS, speed, and ETA from FFmpeg output
- Queue jobs now show detailed progress metrics matching direct conversions
- Stats stored in job.Config for display in the conversion stats bar
2. **AMD AMF Hardware Acceleration** (main.go)
- Added "amf" to hardware acceleration options
- Support for h264_amf, hevc_amf, and av1_amf encoders
- Added AMF-specific error detection in FFmpeg output parsing
3. **DVD Format Resolution Forcing** (main.go:1080-1103, 4504-4517)
- Removed automatic resolution forcing when DVD format is selected
- Removed -target parameter usage which was forcing 720×480/720×576
- Resolution now defaults to "Source" unless explicitly changed
- DVD compliance maintained through manual bitrate/GOP/codec parameters
**Windows Build Improvements:**
- Updated build.bat to enable CGO (required for Fyne/OpenGL)
- Added automatic GCC/MinGW-w64 detection and installation
- Automated setup via winget for one-command Windows builds
- Improved error messages with fallback manual instructions
**Documentation:**
- Added comprehensive Windows setup guides
- Created platform.go for future platform-specific code
- Updated .gitignore for Windows build artifacts
All changes tested and working. Ready for production use.
