feat: add parcel-sync module (eTerra ANCPI integration with PostGIS)

- 31 eTerra layer catalog (terenuri, cladiri, documentatii, administrativ)
- Incremental sync engine (OBJECTID comparison, only downloads new features)
- PostGIS-ready Prisma schema (GisFeature, GisSyncRun, GisUat models)
- 7 API routes (/api/eterra/login, count, sync, features, layers/summary, progress, sync-status)
- Full UI with 3 tabs (Sincronizare, Parcele, Istoric)
- Env var auth (ETERRA_USERNAME / ETERRA_PASSWORD)
- Real-time sync progress tracking with polling

prisma/schema.prisma

@@ -1,10 +1,12 @@
 generator client {
-  provider = "prisma-client-js"
+  provider        = "prisma-client-js"
+  previewFeatures = ["postgresqlExtensions"]
 }
 
 datasource db {
-  provider = "postgresql"
-  url      = env("DATABASE_URL")
+  provider   = "postgresql"
+  url        = env("DATABASE_URL")
+  extensions = [postgis]
 }
 
 model KeyValueStore {
@@ -18,3 +20,59 @@ model KeyValueStore {
   @@unique([namespace, key])
   @@index([namespace])
 }
+
+// ─── GIS: eTerra ParcelSync ────────────────────────────────────────
+
+model GisFeature {
+  id           String   @id @default(uuid())
+  layerId      String   // e.g. TERENURI_ACTIVE, CLADIRI_ACTIVE
+  siruta       String
+  objectId     Int      // eTerra OBJECTID (unique per layer)
+  inspireId    String?
+  cadastralRef String?  // NATIONAL_CADASTRAL_REFERENCE
+  areaValue    Float?
+  isActive     Boolean  @default(true)
+  attributes   Json     // all raw eTerra attributes
+  geometry     Json?    // GeoJSON geometry (Polygon/MultiPolygon)
+  syncRunId    String?
+  projectId    String?  // link to project tag
+  createdAt    DateTime @default(now())
+  updatedAt    DateTime @updatedAt
+
+  syncRun GisSyncRun? @relation(fields: [syncRunId], references: [id])
+
+  @@unique([layerId, objectId])
+  @@index([siruta])
+  @@index([cadastralRef])
+  @@index([layerId, siruta])
+  @@index([projectId])
+}
+
+model GisSyncRun {
+  id              String    @id @default(uuid())
+  siruta          String
+  uatName         String?
+  layerId         String
+  status          String    @default("pending") // pending | running | done | error
+  totalRemote     Int       @default(0)
+  totalLocal      Int       @default(0)
+  newFeatures     Int       @default(0)
+  removedFeatures Int       @default(0)
+  startedAt       DateTime  @default(now())
+  completedAt     DateTime?
+  errorMessage    String?
+  features        GisFeature[]
+
+  @@index([siruta])
+  @@index([layerId])
+  @@index([siruta, layerId])
+}
+
+model GisUat {
+  siruta    String   @id
+  name      String
+  county    String?
+  updatedAt DateTime @updatedAt
+
+  @@index([name])
+}