more stuff to improve robustness

frontend/src/lib/assert.ts

@@ -0,0 +1,11 @@
+export function assert(condition: boolean, message: string): asserts condition {
+  if (!condition) {
+    const error = new Error(`Assertion failed: ${message}`);
+    if (import.meta.env.DEV) {
+      console.error('[Assertion]', message, error.stack);
+      throw error;
+    } else {
+      console.warn('[Assertion] (prod silenced):', message);
+    }
+  }
+}

frontend/src/lib/tauri-bridge.ts

@@ -120,4 +120,20 @@ window.electronAPI = {
   deleteModel: (path: string): Promise<void> => {
     return invoke('delete_model', { path });
   },
+
+  logError: (message: string, stack: string, componentStack: string): Promise<void> => {
+    return invoke('log_error', { message, stack, componentStack });
+  },
+
+  writeAutosave: (data: string): Promise<void> => {
+    return invoke('write_autosave', { data });
+  },
+
+  readAutosave: (): Promise<string | null> => {
+    return invoke('read_autosave');
+  },
+
+  deleteAutosave: (): Promise<void> => {
+    return invoke('delete_autosave');
+  },
 };