fix(sync): detect deleted orders and invoices in ROA

Previously, orders deleted from Oracle (sters=1) remained as IMPORTED
in SQLite, and deleted invoices kept stale cache data. Now the refresh
button and sync cycle re-verify all imported orders against Oracle:
- Deleted orders → marked DELETED_IN_ROA with cleared id_comanda
- Deleted invoices → invoice cache fields cleared
- New status badge for DELETED_IN_ROA in dashboard and logs

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

api/app/services/invoice_service.py

@@ -43,3 +43,33 @@ def check_invoices_for_orders(id_comanda_list: list) -> dict:
         database.pool.release(conn)
 
     return result
+
+
+def check_orders_exist(id_comanda_list: list) -> set:
+    """Check which id_comanda values still exist in Oracle COMENZI (sters=0).
+    Returns set of id_comanda that exist.
+    """
+    if not id_comanda_list or database.pool is None:
+        return set()
+
+    existing = set()
+    conn = database.get_oracle_connection()
+    try:
+        with conn.cursor() as cur:
+            for i in range(0, len(id_comanda_list), 500):
+                batch = id_comanda_list[i:i+500]
+                placeholders = ",".join([f":c{j}" for j in range(len(batch))])
+                params = {f"c{j}": cid for j, cid in enumerate(batch)}
+
+                cur.execute(f"""
+                    SELECT id_comanda FROM COMENZI
+                    WHERE id_comanda IN ({placeholders}) AND sters = 0
+                """, params)
+                for row in cur:
+                    existing.add(row[0])
+    except Exception as e:
+        logger.warning(f"Order existence check failed: {e}")
+    finally:
+        database.pool.release(conn)
+
+    return existing