feat(parcel-sync): store UATs in PostgreSQL, eliminate repeated eTerra calls

- GisUat table now includes workspacePk column (created via raw SQL)
- GET /api/eterra/uats serves from PostgreSQL  instant, no eTerra login needed
- POST /api/eterra/uats triggers sync check: compares county count with DB,
  only does full eTerra fetch if data differs or DB is empty
- Frontend loads UATs from DB on mount (fast), falls back to uat.json if empty
- On eTerra connect, fires POST to sync-check; if data changed, reloads from DB
- Workspace cache populated from DB on GET for search route performance

prisma/schema.prisma

@@ -69,10 +69,12 @@ model GisSyncRun {
 }
 
 model GisUat {
-  siruta    String   @id
-  name      String
-  county    String?
-  updatedAt DateTime @updatedAt
+  siruta      String   @id
+  name        String
+  county      String?
+  workspacePk Int?
+  updatedAt   DateTime @updatedAt
 
   @@index([name])
+  @@index([county])
 }