fix(toolbar): watch active ref for always-mounted views (AgentsView, ViewerView)

Views mounted via v-if+CSS-hide never unmount, so onMounted/onUnmounted only fire
once. When a RouterView (Tests) unmounts it clears _config, and the always-mounted
view never restores it. Fix: provideToolbar accepts optional active ref and uses
watch() instead of lifecycle hooks for those views.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

src/composables/useToolbar.ts

@@ -9,7 +9,7 @@
  * Views that don't provide → toolbar shows nothing (login, home).
  */
 
-import { onMounted, onUnmounted, ref, type Ref } from 'vue';
+import { onMounted, onUnmounted, ref, watch, type Ref } from 'vue';
 
 // --- Types ---
 
@@ -35,16 +35,24 @@ export interface ToolbarConfig {
 const _config = ref<ToolbarConfig | null>(null);
 let _mountVersion = 0;
 
-export function provideToolbar(config: ToolbarConfig) {
+/**
+ * Register toolbar config for the active view.
+ *
+ * Pass `active` for always-mounted views (v-if + CSS hide, e.g. AgentsView, ViewerView).
+ * Omit `active` for route-mounted views (RouterView) — uses onMounted/onUnmounted.
+ */
+export function provideToolbar(config: ToolbarConfig, active?: Ref<boolean>) {
     let myVersion = 0;
-    onMounted(() => {
-        myVersion = ++_mountVersion;
-        _config.value = config;
-    });
-    onUnmounted(() => {
-        // Only clear if no newer component has taken ownership since we mounted.
-        if (myVersion === _mountVersion) _config.value = null;
-    });
+
+    function activate() { myVersion = ++_mountVersion; _config.value = config; }
+    function deactivate() { if (myVersion === _mountVersion) _config.value = null; }
+
+    if (active !== undefined) {
+        watch(active, (isActive) => { isActive ? activate() : deactivate(); }, { immediate: true });
+    } else {
+        onMounted(activate);
+        onUnmounted(deactivate);
+    }
 }
 
 export function injectToolbar(): Ref<ToolbarConfig | null> {

src/views/AgentsView.vue

@@ -98,7 +98,8 @@ const { connected, send: wsSend } = ws;
 const { isLoggedIn } = auth;
 const { selectedAgent, selectedMode, filteredAgents, defaultAgent, allAgents } = agents;
 
-// Toolbar — wrap chatStore state into ToolbarConnection shape
+// Toolbar — always-mounted view: pass viewActive so config tracks route, not lifecycle
+const viewActive = computed(() => agentsRoute.name === 'nyx');
 const chatStore = useChatStore();
 provideToolbar({
     groups: ['quad-view', 'themes', 'panels'],
@@ -119,7 +120,7 @@ provideToolbar({
             Mode:    selectedMode.value,
         }),
     },
-});
+}, viewActive);
 
 // Agent picker — disabled for now (auto-select default agent)
 // TODO: re-enable when multi-agent UX is designed
@@ -160,8 +161,6 @@ watch(
     { immediate: true },
 );
 
-const viewActive = computed(() => agentsRoute.name === 'nyx');
-
 // HUD state from ChatPane (for debug panels)
 const hudState = ref({ hudTree: [] as any[], hudVersion: 0, connected: false });
 function onHudUpdate(payload: { hudTree: any[]; hudVersion: number; connected: boolean }) {

src/views/ViewerView.vue

@@ -88,8 +88,11 @@ import { useViewer } from '../composables/useViewer';
 import { provideToolbar } from '../composables/useToolbar';
 import { computed } from 'vue';
 
-provideToolbar({ groups: ['themes'] });
+import { useRoute } from 'vue-router';
 import { getApiBase } from '../utils/apiBase';
+const _route = useRoute();
+const _viewActive = computed(() => _route.name === 'viewer');
+provideToolbar({ groups: ['themes'] }, _viewActive);
 
 const {
   fstoken, viewerRoots, currentPath,