FG Scan form validation improvements with warehouse module updates

- Fixed 3 JavaScript syntax errors in fg_scan.html (lines 951, 840-950, 1175-1215)
- Restored form field validation with proper null safety checks
- Re-enabled auto-advance between form fields
- Re-enabled CP code auto-complete with hyphen detection
- Updated validation error messages with clear format specifications and examples
- Added autocomplete='off' to all input fields
- Removed auto-prefix correction feature
- Updated warehouse routes and modules for box assignment workflow
- Added/improved database initialization scripts
- Updated requirements.txt dependencies

Format specifications implemented:
- Operator Code: OP + 2 digits (example: OP01, OP99)
- CP Code: CP + 8 digits + hyphen + 4 digits (example: CP00000000-0001)
- OC1/OC2 Codes: OC + 2 digits (example: OC01, OC99)
- Defect Code: 3 digits only

app/modules/settings/routes.py

@@ -874,7 +874,12 @@ def get_database_tables():
 
 @settings_bp.route('/api/database/truncate', methods=['POST'])
 def truncate_table():
-    """Truncate (clear) a database table"""
+    """Truncate (clear) a database table
+    
+    Special handling for warehouse_locations table:
+    - Preserves the 2 default locations: FG_INCOMING and TRUCK_LOADING
+    - Deletes only user-created locations
+    """
     if 'user_id' not in session:
         return jsonify({'error': 'Unauthorized'}), 401
     
@@ -898,12 +903,30 @@ def truncate_table():
             cursor.close()
             return jsonify({'error': 'Table not found'}), 404
         
-        # Truncate the table
-        cursor.execute(f'TRUNCATE TABLE {table}')
-        conn.commit()
-        cursor.close()
-        
-        return jsonify({'success': True, 'message': f'Table {table} cleared successfully'})
+        # Special handling for warehouse_locations table
+        if table == 'warehouse_locations':
+            # Delete all rows EXCEPT the 2 default locations
+            cursor.execute("""
+                DELETE FROM warehouse_locations 
+                WHERE location_code NOT IN ('FG_INCOMING', 'TRUCK_LOADING')
+            """)
+            conn.commit()
+            deleted_count = cursor.rowcount
+            cursor.close()
+            
+            return jsonify({
+                'success': True, 
+                'message': f'Table {table} cleared successfully ({deleted_count} rows deleted)',
+                'preserved_count': 2,
+                'preserved_locations': ['FG_INCOMING', 'TRUCK_LOADING']
+            })
+        else:
+            # For all other tables, perform standard truncate
+            cursor.execute(f'TRUNCATE TABLE {table}')
+            conn.commit()
+            cursor.close()
+            
+            return jsonify({'success': True, 'message': f'Table {table} cleared successfully'})
     
     except Exception as e:
         return jsonify({'error': str(e)}), 500