The row cache rebuilt a string for every line of the file after each edit
and had one production caller left (filetype detection in the ImGui
frontend, which needs only the first line). Removed with it: rows_,
nrows_, the dirty flag set on every edit, ensure_rows_cache and a mutex
guarding only that cache. Tests read lines with GetLineString, Nrows or,
where they compare every line, a test-only LinesForTests().
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_015rcVQiiWyTzoNrsvLSaAfB
- Introduced SwapManager for sidecar journaling of buffer mutations, with a safe recovery mechanism.
- Added group undo/redo functionality, allowing atomic grouping of related edits.
- Implemented `SwapRecorder` and integrated it as a callback interface for mutations.
- Added unit tests for swap journaling (save/load/replay) and undo grouping.
- Refactored undo to support group tracking and ID management.
- Updated CMake to include the new tests and swap journaling logic.
Claude
kyle