fix(model): unload model from memory before deletion

api/routers/model.py

@@ -39,6 +39,17 @@ async def switch_model(model_id: str):
         raise HTTPException(400, str(e))
 
 
+@router.post("/unload/{model_id}")
+async def unload_model(model_id: str):
+    """Unloads a model from memory so its files can be safely deleted."""
+    try:
+        gen = generator_registry.get_generator(model_id)
+        gen.unload()
+        return {"unloaded": True}
+    except ValueError:
+        return {"unloaded": True}  # already not loaded, that's fine
+
+
 @router.get("/hf-download")
 async def hf_download(repo_id: str, model_id: str):
     """

electron/main/ipc-handlers.ts

@@ -96,13 +96,18 @@ export function setupIpcHandlers(pythonBridge: PythonBridge, getWindow: WindowGe
     return result.canceled ? null : result.filePath
   })
 
-  ipcMain.handle('model:delete', async (_, modelId: string): Promise<boolean> => {
+  ipcMain.handle('model:delete', async (_, modelId: string): Promise<{ success: boolean; error?: string }> => {
     const modelDir = join(app.getPath('userData'), 'models', modelId)
     try {
-      await rmAsync(modelDir, { recursive: true, force: true })
-      return true
+      await axios.post(`${API_BASE_URL}/model/unload/${encodeURIComponent(modelId)}`, {}, { timeout: 5000 })
     } catch {
-      return false
+      // unload is best-effort — proceed with deletion anyway
+    }
+    try {
+      await rmAsync(modelDir, { recursive: true, force: true })
+      return { success: true }
+    } catch (err) {
+      return { success: false, error: String(err) }
     }
   })
 

src/areas/models/ModelsPage.tsx

@@ -31,6 +31,7 @@ export default function ModelsPage(): JSX.Element {
   const [models,        setModels]        = useState<LocalModel[]>([])
   const [downloading,   setDownloading]   = useState<Record<string, number>>({})
   const [deleteTarget,  setDeleteTarget]  = useState<LocalModel | null>(null)
+  const [deleteError,   setDeleteError]   = useState<string | null>(null)
   const [uninstallTarget, setUninstallTarget] = useState<string | null>(null)
 
   // GitHub extension install form
@@ -64,8 +65,13 @@ export default function ModelsPage(): JSX.Element {
   }, [installError])
 
   async function handleDelete(model: LocalModel) {
-    await window.electron.model.delete(model.id)
+    const result = await window.electron.model.delete(model.id)
+    if (!result.success) {
+      setDeleteError('Failed to delete the model. Try restarting the app and deleting again.')
+      return
+    }
     setDeleteTarget(null)
+    setDeleteError(null)
     refresh()
   }
 
@@ -331,12 +337,12 @@ export default function ModelsPage(): JSX.Element {
       {deleteTarget && (
         <ConfirmModal
           title={`Uninstall ${formatModelName(deleteTarget.id)}?`}
-          description="This will permanently delete the model weights from your disk. You can re-download it anytime."
+          description={deleteError ?? "This will permanently delete the model weights from your disk. You can re-download it anytime."}
           confirmLabel="Uninstall"
           cancelLabel="Keep"
           variant="danger"
           onConfirm={() => handleDelete(deleteTarget)}
-          onCancel={() => setDeleteTarget(null)}
+          onCancel={() => { setDeleteTarget(null); setDeleteError(null) }}
         />
       )}
 

src/shared/types/electron.d.ts

@@ -41,7 +41,7 @@ declare global {
         listDownloaded: () => Promise<{ id: string; name: string; size_gb: number }[]>
         isDownloaded:   (modelId: string) => Promise<boolean>
         download:       (repoId: string, modelId: string) => Promise<{ success: boolean; error?: string }>
-        delete:         (modelId: string) => Promise<boolean>
+        delete:         (modelId: string) => Promise<{ success: boolean; error?: string }>
         onProgress:     (cb: (data: { modelId: string; percent: number }) => void) => void
         offProgress:    () => void
       }