fix: improve 'not our ref' error messages and warn about multi-OID fetch bug

When git fetch fails with 'upload-pack: not our ref', git stops at the first
missing OID and doesn't attempt to fetch remaining OIDs. This means if we
request 5 OIDs and the first is missing, we never try the other 4 (which may
exist on the remote).

Changes:
- Parse missing OID from stderr for clearer error messages
- Single OID case: 'remote missing only oid requested: <oid>'
- Multi OID case: Log WARNING and indicate other OIDs weren't attempted
- Identifies the bug that needs retry logic to fetch OIDs individually

0 files changed, 0 insertions, 0 deletions