These files are machine-specific and should never be committed or cause
conflicts when syncing vaults across devices.
Changes:
- init_repo() now writes .gitignore with .laputa-cache.json and
.laputa/settings.json excluded before the first commit
- .DS_Store and common editor artifacts also excluded
- openConflictFileRef falls back to openLocalFile() for non-note files
so 'Open in editor' works for .json conflict files (opens in system
default app, e.g. TextEdit/VS Code)
- Removed stale git.rs (replaced by git/mod.rs from refactor)
- 2 new Rust tests for .gitignore creation behavior
d7c210222c