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>

prisma/schema.prisma

@@ -19,6 +19,36 @@ model KeyValueStore {
   @@index([namespace])
 }
 
+// ─── GIS: Sync Scheduling ──────────────────────────────────────────
+
+model GisSyncRule {
+  id                String    @id @default(uuid())
+  siruta            String?   /// Set = UAT-specific rule
+  county            String?   /// Set = county-wide default rule
+  frequency         String    /// "3x-daily"|"daily"|"weekly"|"monthly"|"manual"
+  syncTerenuri      Boolean   @default(true)
+  syncCladiri       Boolean   @default(true)
+  syncNoGeom        Boolean   @default(false)
+  syncEnrich        Boolean   @default(false)
+  priority          Int       @default(5) /// 1=highest, 10=lowest
+  enabled           Boolean   @default(true)
+  allowedHoursStart Int?      /// null = no restriction, e.g. 1 for 01:00
+  allowedHoursEnd   Int?      /// e.g. 5 for 05:00
+  allowedDays       String?   /// e.g. "1,2,3,4,5" for weekdays, null = all days
+  lastSyncAt        DateTime?
+  lastSyncStatus    String?   /// "done"|"error"
+  lastSyncError     String?
+  nextDueAt         DateTime?
+  label             String?   /// Human-readable note
+  createdAt         DateTime  @default(now())
+  updatedAt         DateTime  @updatedAt
+
+  @@unique([siruta, county])
+  @@index([enabled, nextDueAt])
+  @@index([county])
+  @@index([frequency])
+}
+
 // ─── GIS: eTerra ParcelSync ────────────────────────────────────────
 
 model GisFeature {