feat: add POST /api/cases/parties to store UYAP taraf bilgileri

The UYAP extension now captures the davaci/davali/sanik + vekil data
from the "Taraf Bilgileri" tab and sends it once per case. This
endpoint finds/creates the matching case by title (same lookup used
by registerLocalDocument, now shared via lib/caseLookup.ts) and stores
it in a new cases.parties column - a much more reliable source for
the case detail screen's "Taraflar" info than the AI's own guess from
OCR'd document text.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

src/routes/case.routes.ts

@@ -1,11 +1,12 @@
 import { Router } from 'express';
 import { requireAuth } from '../middleware/auth';
-import { createCase, deleteCase, summarizeCase } from '../controllers/case.controller';
+import { createCase, deleteCase, summarizeCase, updateCaseParties } from '../controllers/case.controller';
 
 const router = Router();
 
 router.post('/', requireAuth, createCase);
 router.delete('/:caseId', requireAuth, deleteCase);
 router.post('/:caseId/summarize', requireAuth, summarizeCase);
+router.post('/parties', requireAuth, updateCaseParties);
 
 export default router;