The timestamp-only deduplication feature causes data loss when
export_hashes table gets out of sync with JSONL file (after git
operations, imports, etc). This leads to exports skipping issues
that aren't actually in the file.
Symptoms we saw:
- Export reports 'Skipped 128 issues with timestamp-only changes'
- JSONL only has 38 lines but DB has 149 issues
- Two repos on same commit show different issue counts
- Auto-import doesn't trigger (hash matches despite missing data)
Fix: Disable the feature entirely until we can implement proper
JSONL integrity validation (see bd-160 for proposed solutions).
bafa8374f9