fix: all lint errors, test + lint pre-commit passing

Frontend:
- Split nodeTypes/edgeTypes into separate .ts files (react-refresh)
- Remove setState-in-effect in NodeModal (key prop reset)
- Fix handleSave accessed before declaration (useRef pattern)
- Exclude src/components/ui/** from eslint (shadcn generated)
- Use defineConfig from vitest/config for test type support

Backend:
- ruff --fix: sort imports, datetime.UTC alias
- Raise line-length to 120, ignore E501 in tests
- Break long update_node/update_edge signatures
- pyproject.toml: per-file-ignores for tests

frontend/src/components/canvas/edges/index.tsx

@@ -22,13 +22,13 @@ const EDGE_STYLES: Record<EdgeType, React.CSSProperties> = {
   virtual: { stroke: '#8b949e', strokeWidth: 1, strokeDasharray: '4 4' },
 }
 
-function HomelableEdge({ id, sourceX, sourceY, targetX, targetY, sourcePosition, targetPosition, data, selected }: EdgeProps<Edge<EdgeData>>) {
+export function HomelableEdge({ id, sourceX, sourceY, targetX, targetY, sourcePosition, targetPosition, data, selected }: EdgeProps<Edge<EdgeData>>) {
   const [edgePath, labelX, labelY] = getBezierPath({ sourceX, sourceY, sourcePosition, targetX, targetY, targetPosition })
 
   const edgeType: EdgeType = data?.type ?? 'ethernet'
   const style: React.CSSProperties = {
     ...EDGE_STYLES[edgeType],
-    ...(edgeType === 'vlan' ? { stroke: getVlanColor(data?.vlan_id) } : {}),
+    ...(edgeType === 'vlan' ? { stroke: getVlanColor(data?.vlan_id as number | undefined) } : {}),
     ...(selected ? { stroke: '#00d4ff', filter: 'drop-shadow(0 0 4px #00d4ff88)' } : {}),
   }
 
@@ -46,18 +46,10 @@ function HomelableEdge({ id, sourceX, sourceY, targetX, targetY, sourcePosition,
               border: '1px solid #30363d',
             }}
           >
-            {data.label}
+            {data.label as string}
           </div>
         </EdgeLabelRenderer>
       )}
     </>
   )
 }
-
-export const edgeTypes = {
-  ethernet: HomelableEdge,
-  wifi: HomelableEdge,
-  iot: HomelableEdge,
-  vlan: HomelableEdge,
-  virtual: HomelableEdge,
-}