feat(parcel-sync): smart delta sync + fix HAS_BUILDING bug

- Fix: geoportal/enrich endpoint now looks up CLADIRI_ACTIVE from DB
  instead of hardcoding HAS_BUILDING=0, BUILD_LEGAL=0
- Quick-count check: skip OBJECTID comparison when remote==local count
- VALID_FROM delta: detect attribute changes on existing parcels and
  mark them for re-enrichment (catches spatial validity changes)
- Early bailout: skip all eTerra API calls when 0 features need enrichment
- Rolling doc check: probe 200 oldest-enriched parcels for new
  documentation activity (catches ownership/CF changes VALID_FROM misses)
- Targeted doc fetch: only fetch documentation for immovable PKs that
  actually need enrichment instead of all 10k+

Daily sync cost reduced from ~300+ API calls / 1-2h to ~6-10 calls / 10-15s.

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

src/app/api/geoportal/enrich/route.ts

@@ -75,6 +75,34 @@ export async function POST(req: Request) {
       return NextResponse.json({ error: "Parcela negasita in registrul eTerra" }, { status: 404 });
     }
 
+    // Building cross-ref: check CLADIRI_ACTIVE in local DB for this parcel
+    let hasBuilding = 0;
+    let buildLegal = 0;
+    const baseCad = cadRef.includes("-") ? cadRef.split("-")[0]! : cadRef;
+    if (baseCad) {
+      const cladiri = await prisma.gisFeature.findMany({
+        where: {
+          layerId: "CLADIRI_ACTIVE",
+          siruta: feature.siruta,
+          OR: [
+            { cadastralRef: { startsWith: baseCad + "-" } },
+            { cadastralRef: baseCad },
+          ],
+        },
+        select: { attributes: true },
+      });
+      for (const c of cladiri) {
+        const attrs = c.attributes as Record<string, unknown>;
+        hasBuilding = 1;
+        if (
+          Number(attrs.IS_LEGAL ?? 0) === 1 ||
+          String(attrs.IS_LEGAL ?? "").toLowerCase() === "true"
+        ) {
+          buildLegal = 1;
+        }
+      }
+    }
+
     // Convert to enrichment format (same as enrichFeatures uses)
     const enrichment = {
       NR_CAD: match.nrCad || cadRef,
@@ -89,8 +117,8 @@ export async function POST(req: Request) {
       SOLICITANT: match.solicitant || "",
       INTRAVILAN: match.intravilan || "",
       CATEGORIE_FOLOSINTA: match.categorieFolosinta || "",
-      HAS_BUILDING: 0,
-      BUILD_LEGAL: 0,
+      HAS_BUILDING: hasBuilding,
+      BUILD_LEGAL: buildLegal,
     };
 
     // Persist