- handle DECSET ?47 as an alternate screen mode so tmux clear redraws don't overlay stale content in screenshots
- keep AltScreen mode checks aligned with 47/1047/1048/1049 variants used by full-screen TUIs
- document the screenshot debugging workflow in .github/skills/screenshot-debugging/SKILL.md for repeatable escape-sequence analysis
- Add get_screen_snapshot() method that doesn't mutate terminal state
- Use change counter for reliable activity detection instead of dirty flag
- Update screenshot handler to use non-mutating snapshot method
- Refactor tests to use shared fixtures and reduce duplication
- Update copilot-instructions.md with detailed Makefile usage
Add isTerminalReady() check before calling fitAddon.proposeDimensions()
in the initial fit loop to prevent 'viewport.scrollBarWidth' TypeError
when terminal is not fully initialized.