0.3.0

chore(blackbox): mark feature as upcoming

User Request:
- Replace the Game Blackbox use button with a disabled preparing state
- Move blackbox notes out of the 0.3.0 user changelog into development
- Set the application version to 0.3.0 and create the Windows package

AI Work Summary:
- Added a shared availability flag and disabled the blackbox UI and main-screen controls
- Clear legacy enabled settings during startup so the recorder helper cannot auto-run in 0.3.0
- Changed the advanced feature button to disabled 준비중
- Moved the user-facing blackbox entry to 개발 중 and updated technical continuity records
- Confirmed package metadata is already 0.3.0 and generated the installer and update assets
- Rebuilt the tracked recorder helper during packaging

Key Decisions:
- Disable runtime startup as well as the button so persisted settings cannot bypass the release lock
- Keep the completed implementation in the package for later activation while presenting it as development work

Remaining:
- Manually verify the installed 0.3.0 build shows 준비중 and never launches the recorder helper
- Deployment was not requested and has not been performed

Co-authored-by: Cursor <cursoragent@cursor.com>