feat(sync-management): rule-based sync scheduling page + API

Phase 1 of unified sync scheduler:

- New Prisma model GisSyncRule: per-UAT or per-county sync frequency
  rules with priority, time windows, step selection (T/C/N/E)
- CRUD API: /api/eterra/sync-rules (list, create, update, delete, bulk)
- Global default frequency via KeyValueStore
- /sync-management page with 3 tabs:
  - Reguli: table with filters, add dialog (UAT search + county select)
  - Status: stats cards, frequency distribution, coverage overview
  - Judete: quick county-level frequency assignment
- Monitor page: link to sync management from eTerra actions section

Rule resolution: UAT-specific > county default > global default.
Scheduler engine (Phase 2) will read these rules to automate syncs.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

src/app/(modules)/monitor/page.tsx

@@ -447,7 +447,15 @@ export default function MonitorPage() {
 
           {/* Sync actions */}
           <div>
-            <h3 className="text-xs font-medium text-muted-foreground mb-2 uppercase tracking-wider">Sincronizare eTerra</h3>
+            <div className="flex items-center justify-between mb-2">
+              <h3 className="text-xs font-medium text-muted-foreground uppercase tracking-wider">Sincronizare eTerra</h3>
+              <a
+                href="/sync-management"
+                className="text-xs text-primary hover:underline"
+              >
+                Gestioneaza reguli sync
+              </a>
+            </div>
             <div className="flex flex-wrap gap-3">
               <SyncTestButton
                 label="Sync All Romania"