v0.4.3

Fixed

• ai sync push no longer creates new git blobs for unchanged files — SHA-256 check before shutil.copy2 skips files with identical content, eliminating the primary driver of staging repo pack bloat.
• git gc --auto runs after each sync commit to repack loose objects when needed.
• Memory directory non-markdown files (e.g. .consolidate-lock) are now excluded from sync via should_sync_file, preventing spurious conflict detections and .conflict.conflict cascades.