M10 (task 2013): integrated AppImage — app self-integration (OOBE + Account toggle)

The Linux AppImage can now install itself into the applications menu, so it behaves
like an installed app instead of a loose file.

- Rust (desktop/src-tauri/src/integration.rs): integration_status / integrate_desktop
  / unintegrate_desktop commands — detect $APPIMAGE, copy the AppImage to
  ~/Applications, write ~/.local/share/applications/thoughtsync.desktop + embedded
  icon, update-desktop-database. Registered in lib.rs.
- Frontend: withGlobalTauri exposes window.__TAURI__.core.invoke; desktop/bridge.ts
  (isDesktop + typed invoke, NO @tauri-apps/api dep -> web bundle unaffected);
  DesktopIntegrationPrompt (first-run OOBE, remembered) mounted in App.vue;
  AccountView "Desktop app" add/remove control. All desktop-guarded -> no-ops on web.
- desktop.yml: upload the .deb + .AppImage as a run artifact (continue-on-error) so
  the build is downloadable for hand-testing.

Verified by CI: ci.yml (vue-tsc) for the frontend, desktop.yml (cargo + tauri build)
for the Rust + AppImage.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01FRgehjoz7Yv8LkUfADxACm

frontend/src/views/AccountView.vue

@@ -5,6 +5,7 @@ import { useUiStore } from "../stores/ui";
 import BaseButton from "../components/BaseButton.vue";
 import BaseInput from "../components/BaseInput.vue";
 import Icon from "../components/Icon.vue";
+import { isDesktop, desktop as desktopBridge, type IntegrationStatus } from "../desktop/bridge";
 
 // Per-user (not admin) management of linked native clients — the Tauri desktop and
 // Android apps authenticate sync with a device bearer token issued here.
@@ -17,6 +18,10 @@ const creating = ref(false);
 // The freshly-issued plaintext token — shown ONCE (never retrievable again).
 const freshToken = ref("");
 
+// Desktop-app self-integration (Linux AppImage only; the card is hidden otherwise).
+const desktopStatus = ref<IntegrationStatus | null>(null);
+const desktopBusy = ref(false);
+
 async function load() {
   error.value = "";
   try {
@@ -63,7 +68,37 @@ function fmt(iso: string | null): string {
   return new Date(iso).toLocaleString();
 }
 
-onMounted(load);
+async function loadDesktop() {
+  if (!isDesktop()) return;
+  try {
+    desktopStatus.value = await desktopBridge.integrationStatus();
+  } catch {
+    desktopStatus.value = null;
+  }
+}
+
+async function toggleIntegration() {
+  desktopBusy.value = true;
+  try {
+    desktopStatus.value = desktopStatus.value?.is_integrated
+      ? await desktopBridge.unintegrate()
+      : await desktopBridge.integrate();
+    ui.showToast(
+      desktopStatus.value?.is_integrated
+        ? "Added to your applications menu."
+        : "Removed from your applications menu.",
+    );
+  } catch (e) {
+    ui.showToast((e as { message?: string }).message ?? "Couldn't update the menu entry.");
+  } finally {
+    desktopBusy.value = false;
+  }
+}
+
+onMounted(() => {
+  void load();
+  void loadDesktop();
+});
 </script>
 
 <template>
@@ -91,6 +126,31 @@ onMounted(load);
       paste it into the app when it asks to connect. You can revoke a device at any time.
     </p>
 
+    <!-- Desktop app self-integration (Linux AppImage only) -->
+    <section
+      v-if="desktopStatus?.is_appimage"
+      class="mb-6 flex items-center justify-between gap-4 rounded-xl border border-neutral-200 p-4 dark:border-neutral-800"
+    >
+      <div class="min-w-0">
+        <p class="text-sm font-medium text-neutral-800 dark:text-neutral-100">Desktop app</p>
+        <p class="mt-0.5 text-xs text-neutral-400">
+          {{
+            desktopStatus.is_integrated
+              ? "ThoughtSync is in your applications menu."
+              : "Add ThoughtSync to your applications menu to launch it like an installed app."
+          }}
+        </p>
+      </div>
+      <BaseButton
+        :variant="desktopStatus.is_integrated ? 'ghost' : 'primary'"
+        :loading="desktopBusy"
+        class="shrink-0"
+        @click="toggleIntegration"
+      >
+        {{ desktopStatus.is_integrated ? "Remove" : "Add to applications" }}
+      </BaseButton>
+    </section>
+
     <!-- One-time token reveal -->
     <div
       v-if="freshToken"