fix(ai): initialize conversation bindings before default action selection

apps/desktop/src/components/editor/AiAssistant.vue

@@ -327,19 +327,6 @@ let defaultModeInitialized = false;
 let initialConversationStateLoaded = false;
 let initialConversationRestored = false;
 let assistantViewMounted = false;
-watch(
-  () => settings.isAiConfigLoaded,
-  (loaded) => {
-    if (loaded && !defaultModeInitialized) {
-      assistantMode.value = settings.defaultAiMode;
-      // Same apply-once rule as the mode: later setting changes must not
-      // disturb an active conversation.
-      activeAction.value = resolveDefaultActionSelection(settings.defaultAiMode);
-      defaultModeInitialized = true;
-    }
-  },
-  { immediate: true },
-);
 const currentSessionId = ref("");
 const conversationId = ref("");
 const conversations = ref<AiConversation[]>([]);
@@ -368,6 +355,25 @@ const boundConnection = computed(() => (boundConnectionId.value ? connectionStor
 const boundDatabase = computed(() => conversationBinding.value.database);
 const boundSchema = computed(() => conversationBinding.value.schema);
 
+// `immediate` runs this during setup whenever the AI config finished loading
+// before the panel mounted (the usual case: the app loads it at startup), and
+// `resolveDefaultActionSelection` reads `boundConnection`. It must therefore
+// stay below the binding computeds, or setup throws a TDZ ReferenceError and
+// the panel never mounts.
+watch(
+  () => settings.isAiConfigLoaded,
+  (loaded) => {
+    if (loaded && !defaultModeInitialized) {
+      assistantMode.value = settings.defaultAiMode;
+      // Same apply-once rule as the mode: later setting changes must not
+      // disturb an active conversation.
+      activeAction.value = resolveDefaultActionSelection(settings.defaultAiMode);
+      defaultModeInitialized = true;
+    }
+  },
+  { immediate: true },
+);
+
 /**
  * Binding the visible conversation's *active run* is executing against.
  *

apps/desktop/src/components/editor/__tests__/AiAssistant.mount.spec.ts

@@ -0,0 +1,67 @@
+// @vitest-environment happy-dom
+//
+// Mounted smoke test for the AI panel. The app loads the AI config at startup,
+// so the panel normally mounts with `isAiConfigLoaded` already true and its
+// `immediate` default-selection watcher runs during setup. That path once read
+// `boundConnection` before it was declared, and the TDZ ReferenceError kept the
+// panel from opening at all.
+import { createApp, h } from "vue";
+import { afterEach, describe, expect, it, vi } from "vitest";
+import { createPinia } from "pinia";
+import i18n from "@/i18n";
+import { TooltipProvider } from "@/components/ui/tooltip";
+import AiAssistant from "@/components/editor/AiAssistant.vue";
+import { useSettingsStore } from "@/stores/settingsStore";
+
+vi.mock("@/lib/backend/api", async (importOriginal) => {
+  const actual = await importOriginal<Record<string, unknown>>();
+  const empty = () => Promise.resolve([]);
+  return {
+    ...actual,
+    loadAiConversations: empty,
+    loadAiRuns: empty,
+    readUserSkills: empty,
+    loadAiConfigs: empty,
+    loadPromptTemplates: empty,
+    getAiGlobalCustomInstructions: () => Promise.resolve(""),
+    saveAiChatSelection: () => Promise.resolve(),
+    loadAiChatSelection: () => Promise.resolve(null),
+  };
+});
+
+const cleanups: Array<() => void> = [];
+
+afterEach(() => {
+  while (cleanups.length) cleanups.pop()?.();
+});
+
+async function mountPanel(aiConfigLoaded: boolean): Promise<unknown[]> {
+  const pinia = createPinia();
+  const errors: unknown[] = [];
+  const app = createApp({ render: () => h(TooltipProvider, () => h(AiAssistant)) });
+  app.use(pinia);
+  app.use(i18n);
+  app.config.errorHandler = (error) => errors.push(error);
+  app.config.warnHandler = () => {};
+  useSettingsStore(pinia).isAiConfigLoaded = aiConfigLoaded;
+  const container = document.createElement("div");
+  document.body.append(container);
+  app.mount(container);
+  cleanups.push(() => {
+    app.unmount();
+    container.remove();
+  });
+  // Let mount-time loads settle so their failures surface here too.
+  await new Promise((resolve) => setTimeout(resolve, 20));
+  return errors;
+}
+
+describe("AiAssistant mount", () => {
+  it("opens when the AI config was loaded before the panel mounted", async () => {
+    expect((await mountPanel(true)).map(String)).toEqual([]);
+  });
+
+  it("opens while the AI config is still loading", async () => {
+    expect((await mountPanel(false)).map(String)).toEqual([]);
+  });
+});