Two bugs causing 'EACCES: permission denied, copyfile' when source
and target are the same path (e.g. wizard with sourceDir == mosaicHome):
1. No same-path guard — syncDirectory tried to copy every file onto
itself; git pack files are read-only (0444) so copyFileSync fails.
2. excludeGit only matched top-level .git — nested .git dirs like
sources/agent-skills/.git were copied, hitting the same permission
issue.
Fixes:
- Early return when resolve(source) === resolve(target)
- Match .git dirs at any depth via dirName and relPath checks
- Skip files inside .git/ paths
Added file-ops.test.ts with 4 tests covering all cases.
