Fix discovery count doubling and apply results errors

- Fix total_discovered_endpoints count to use DISTINCT device_id instead of counting all endpoints
- Fix apply_discovery_results endpoint to handle dictionary data correctly
- Replace object attribute access with dict.get() methods for scan results

Resolves issues where discovery count doubled with each scan and
apply results failed with '[object Object]' errors.

src/dashboard/api.py

@@ -1105,23 +1105,23 @@ async def apply_discovery_results(scan_id: str, station_id: str, pump_id: str, d
         if not result:
             raise HTTPException(status_code=404, detail=f"Discovery scan {scan_id} not found")
         
-        if result.status != DiscoveryStatus.COMPLETED:
+        if result.get("status") != "completed":
             raise HTTPException(status_code=400, detail="Cannot apply incomplete discovery scan")
         
         created_mappings = []
         errors = []
         
-        for endpoint in result.discovered_endpoints:
+        for endpoint in result.get("discovered_endpoints", []):
             try:
                 # Create protocol mapping from discovered endpoint
-                mapping_id = f"{endpoint.device_id}_{data_type}"
+                mapping_id = f"{endpoint.get('device_id')}_{data_type}"
                 
                 protocol_mapping = ProtocolMapping(
                     id=mapping_id,
                     station_id=station_id,
                     pump_id=pump_id,
-                    protocol_type=endpoint.protocol_type,
-                    protocol_address=endpoint.address,
+                    protocol_type=endpoint.get("protocol_type"),
+                    protocol_address=endpoint.get("address"),
                     data_type=data_type,
                     db_source=db_source
                 )
@@ -1132,10 +1132,10 @@ async def apply_discovery_results(scan_id: str, station_id: str, pump_id: str, d
                 if success:
                     created_mappings.append(mapping_id)
                 else:
-                    errors.append(f"Failed to create mapping for {endpoint.device_name}")
+                    errors.append(f"Failed to create mapping for {endpoint.get('device_name')}")
                     
             except Exception as e:
-                errors.append(f"Error creating mapping for {endpoint.device_name}: {str(e)}")
+                errors.append(f"Error creating mapping for {endpoint.get('device_name')}: {str(e)}")
         
         return {
             "success": True,

src/discovery/protocol_discovery_persistent.py

@@ -97,9 +97,9 @@ class PersistentProtocolDiscoveryService:
                     for row in result
                 ]
             
-            # Get total discovered endpoints
+            # Get total discovered endpoints (count unique endpoints across all scans)
             query = text("""
-                SELECT COUNT(*)
+                SELECT COUNT(DISTINCT endpoint->>'device_id')
                 FROM discovery_results dr,
                      jsonb_array_elements(dr.discovered_endpoints) AS endpoint
                 WHERE dr.status = 'completed'