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/App.vue

@@ -1,8 +1,10 @@
 <script setup lang="ts">
 import ToastHost from "./components/ToastHost.vue";
+import DesktopIntegrationPrompt from "./components/DesktopIntegrationPrompt.vue";
 </script>
 
 <template>
   <RouterView />
   <ToastHost />
+  <DesktopIntegrationPrompt />
 </template>

frontend/src/components/DesktopIntegrationPrompt.vue

@@ -0,0 +1,71 @@
+<script setup lang="ts">
+import { onMounted, ref } from "vue";
+import BaseModal from "./BaseModal.vue";
+import BaseButton from "./BaseButton.vue";
+import { isDesktop, desktop } from "../desktop/bridge";
+import { useUiStore } from "../stores/ui";
+
+// First-run prompt (Linux AppImage only) offering to add ThoughtSync to the
+// applications menu so it behaves like an installed app instead of a loose file.
+// Shown once; the choice is remembered. Users who decline can integrate later from
+// Account. No-op on the web build and on already-integrated / non-AppImage runs.
+const DISMISS_KEY = "desktop.integration.prompted";
+
+const ui = useUiStore();
+const show = ref(false);
+const working = ref(false);
+
+onMounted(async () => {
+  if (!isDesktop() || localStorage.getItem(DISMISS_KEY)) return;
+  try {
+    const status = await desktop.integrationStatus();
+    if (status.is_appimage && !status.is_integrated) show.value = true;
+  } catch {
+    /* not an AppImage / no bridge — just don't prompt */
+  }
+});
+
+function dismiss() {
+  localStorage.setItem(DISMISS_KEY, "1");
+  show.value = false;
+}
+
+async function integrate() {
+  working.value = true;
+  try {
+    await desktop.integrate();
+    localStorage.setItem(DISMISS_KEY, "1");
+    show.value = false;
+    ui.showToast("ThoughtSync added to your applications menu.");
+  } catch (e) {
+    ui.showToast((e as { message?: string }).message ?? "Couldn't add to applications.");
+  } finally {
+    working.value = false;
+  }
+}
+</script>
+
+<template>
+  <BaseModal
+    v-if="show"
+    align="center"
+    panel-class="w-full max-w-md shadow-xl"
+    aria-label="Add ThoughtSync to your applications"
+    @close="dismiss"
+  >
+    <div class="p-6">
+      <h2 class="text-lg font-bold tracking-tight text-neutral-900 dark:text-neutral-100">
+        Add ThoughtSync to your applications?
+      </h2>
+      <p class="mt-2 text-sm text-neutral-600 dark:text-neutral-400">
+        We'll add a menu entry so you can launch ThoughtSync from your app launcher, and keep a stable
+        copy in <code class="font-mono text-xs">~/Applications</code> so it isn't lost from Downloads.
+        You can undo this any time from your account.
+      </p>
+      <div class="mt-6 flex justify-end gap-3">
+        <BaseButton variant="ghost" :disabled="working" @click="dismiss">Not now</BaseButton>
+        <BaseButton :loading="working" @click="integrate">Add to applications</BaseButton>
+      </div>
+    </div>
+  </BaseModal>
+</template>

frontend/src/desktop/bridge.ts

@@ -0,0 +1,38 @@
+// Bridge to the Tauri desktop core. On the web build there is no Tauri runtime, so
+// isDesktop() is false and none of these calls run. Uses the global injected by
+// `withGlobalTauri` (tauri.conf.json), so the shared frontend needs no
+// @tauri-apps/api dependency and the web bundle is unaffected.
+
+interface TauriGlobal {
+  core: { invoke: <T>(cmd: string, args?: Record<string, unknown>) => Promise<T> };
+}
+
+declare global {
+  interface Window {
+    __TAURI__?: TauriGlobal;
+  }
+}
+
+export interface IntegrationStatus {
+  is_appimage: boolean;
+  is_integrated: boolean;
+  appimage_path: string | null;
+}
+
+/** True when running inside the Tauri desktop shell (vs. the web build). */
+export function isDesktop(): boolean {
+  return typeof window !== "undefined" && !!window.__TAURI__;
+}
+
+function invoke<T>(cmd: string, args?: Record<string, unknown>): Promise<T> {
+  const tauri = window.__TAURI__;
+  if (!tauri) return Promise.reject(new Error("Not running in the desktop app."));
+  return tauri.core.invoke<T>(cmd, args);
+}
+
+// Desktop (Linux AppImage) self-integration: add/remove an applications-menu entry.
+export const desktop = {
+  integrationStatus: () => invoke<IntegrationStatus>("integration_status"),
+  integrate: () => invoke<IntegrationStatus>("integrate_desktop"),
+  unintegrate: () => invoke<IntegrationStatus>("unintegrate_desktop"),
+};

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"