Guard bulk ID queries against empty lists to prevent PostgreSQL
syntax error (WHERE id IN ()) when batch POST endpoints receive
empty request bodies.
Affected endpoints:
- POST /api/v3/transactions
- POST /api/v3/results
- POST /api/v3/schedules
- POST /api/v3/battingstats
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
Replace per-row Team/Player lookups with bulk IN-list queries before
the validation loop in post_transactions, post_results, post_schedules,
and post_batstats. A 50-move batch now uses 2 queries instead of 150.
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
aiohttp follows 307 redirects but converts POST to GET, silently
dropping the request body. Standardize all @router.post('') to
@router.post('/') so the canonical URL always has a trailing slash,
preventing 307 redirects when clients POST with trailing slashes.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
