fix: resolve ReferenceError accessing scanModels before initialization

Moved the useEffect that auto-scans models below the definition of scanModels to fix a ReferenceError caused by the Temporal Dead Zone (TDZ) when calling a block-scoped useCallback function before it was initialized.

tauri-app/src/features/runtime/useRuntimeManager.ts

@@ -193,14 +193,6 @@ export function useRuntimeManager() {
     };
   }, [refresh]);
 
-  // Auto-scan models when the configured directory changes
-  useEffect(() => {
-    const modelsDir = draftState.liveSnapshot.config.models_dir;
-    if (modelsDir) {
-      scanModels(modelsDir).catch(() => undefined);
-    }
-  }, [draftState.liveSnapshot.config.models_dir, scanModels]);
-
   const openDraft = useCallback(() => {
     setDraftState((current) => {
       const draftConfig = current.isDirty ? current.draftConfig : cloneConfig(current.savedBaseline);
@@ -381,6 +373,14 @@ export function useRuntimeManager() {
     }
   }, []);
 
+  // Auto-scan models when the configured directory changes
+  useEffect(() => {
+    const modelsDir = draftState.liveSnapshot.config.models_dir;
+    if (modelsDir) {
+      scanModels(modelsDir).catch(() => undefined);
+    }
+  }, [draftState.liveSnapshot.config.models_dir, scanModels]);
+
   const commitSavedSnapshot = useCallback((next: RuntimeSnapshot, keepOpen: boolean) => {
     setDraftState((current) => ({
       ...current,