fix: system health is a Settings tab, not a page only the dot reached

The surface shipped at /system with no nav entry, reachable only by
clicking the health dot beside the brand — a target you have to already
suspect something is wrong to go looking for. Operator-flagged: it needs
a path someone can walk to.

Settings is where you go to ask the instance about itself, so the view
becomes a tab there, beside Activity — Activity answers "what is the
queue doing", System answers "is anything left to do it".

- SystemView.vue moves to components/settings/SystemHealthTab.vue; the
  content is unchanged apart from shedding its own container and h1.
- SettingsView adopts useTabQuery (the composable Browse and
  Subscriptions already use) so a tab can be linked TO. The health dot
  now points at ?tab=system, and /system redirects there so the previous
  build's link and any bookmark still land.
- The tab drops its own 10s poll. v-window keeps a visited item mounted
  rather than destroyed, so that timer would have gone on firing behind
  Maintenance — and TopNav already polls the same store every 15s for
  the dot.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01TTjbZZ6JirCMSaJzQV1RhA

frontend/src/components/TopNav.vue

@@ -6,7 +6,8 @@
         <span class="fc-brand__text">FabledCurator</span>
       </RouterLink>
       <RouterLink
-        :to="{ name: 'system' }" class="fc-health" :title="health.label"
+        :to="{ name: 'settings', query: { tab: 'system' } }"
+        class="fc-health" :title="health.label"
         :aria-label="`System health: ${health.label}`"
       >
         <v-icon size="x-small" :color="health.color">{{ health.icon }}</v-icon>
@@ -282,9 +283,9 @@ onUnmounted(() => { if (healthTimer) clearInterval(healthTimer) })
   display: flex;
   align-items: center;
   flex-shrink: 0;
-  /* A RouterLink since milestone 365 — it is the path to /system, not just an
-     indicator. Reset the anchor so turning a span into a link changed nothing
-     about how the nav reads. */
+  /* A RouterLink since milestone 365 — it is the path to the Settings System
+     tab, not just an indicator. Reset the anchor so turning a span into a
+     link changed nothing about how the nav reads. */
   text-decoration: none;
   color: inherit;
   border-radius: 50%;

frontend/src/components/settings/SystemHealthTab.vue

@@ -1,7 +1,10 @@
 <template>
-  <v-container class="py-6" style="max-width: 900px">
+  <!-- A Settings tab, not a page of its own (operator 2026-09-02): the first
+       cut hung this off the health dot alone, which is a target you have to
+       already suspect something to look for. Settings is where someone goes
+       to ask the instance about itself, so it lives beside Activity. -->
+  <div>
     <div class="d-flex align-center mb-1">
-      <h1 class="text-h5">System</h1>
       <v-spacer />
       <span class="fc-sys__checked">
         {{ store.checkedAt ? `checked ${formatRelative(store.checkedAt)}` : 'checking…' }}
@@ -62,23 +65,17 @@
       then neither, and an indicator that reddened on every update would stop
       being read.
     </p>
-  </v-container>
+  </div>
 </template>
 
 <script setup>
-import { onMounted, onUnmounted } from 'vue'
+import { onMounted } from 'vue'
 
-import { useSystemHealthStore } from '../stores/systemHealth.js'
-import { formatRelative } from '../utils/date.js'
+import { useSystemHealthStore } from '../../stores/systemHealth.js'
+import { formatRelative } from '../../utils/date.js'
 
 const store = useSystemHealthStore()
 
-// Slower than the pipeline chip's 8s: liveness changes on the scale of
-// container restarts, not task starts, and this page is open while someone
-// watches it.
-const POLL_MS = 10_000
-let timer = null
-
 function kindLabel(kind) {
   if (kind === 'celery') return 'background worker'
   if (kind === 'agent') return 'GPU agent'
@@ -86,11 +83,13 @@ function kindLabel(kind) {
   return kind
 }
 
-onMounted(() => {
-  store.refresh()
-  timer = setInterval(() => { if (!document.hidden) store.refresh() }, POLL_MS)
-})
-onUnmounted(() => { if (timer) clearInterval(timer) })
+// No timer of its own. TopNav already polls this same pinia store every 15s
+// for the health dot, and it is mounted on every route this tab is reachable
+// from — a second interval here would just double the request rate for a 5s
+// freshness gain. v-window keeps a visited item MOUNTED (hidden, not
+// destroyed), so a local timer would also have kept firing behind Maintenance.
+// One refresh on open, so arriving at the tab doesn't wait out the nav's tick.
+onMounted(() => { store.refresh() })
 </script>
 
 <style scoped>

frontend/src/router.js

@@ -1,6 +1,5 @@
 import { createRouter, createWebHistory, createMemoryHistory } from 'vue-router'
 import SettingsView from './views/SettingsView.vue'
-import SystemView from './views/SystemView.vue'
 import GalleryView from './views/GalleryView.vue'
 import ShowcaseView from './views/ShowcaseView.vue'
 import ExploreView from './views/ExploreView.vue'
@@ -46,12 +45,13 @@ const routes = [
 
   // Settings — config, pinned to the right of the nav (TopNav special-cases it).
   { path: '/settings', name: 'settings', component: SettingsView, meta: { title: 'Settings', stickyChrome: true } },
-  // Deliberately NO meta.title: TopNav builds its nav row from routes that
-  // have one, and this is reached from the health indicator beside the
-  // brand — the place someone already looks when they suspect something is
-  // wrong. A sixth top-level tab for a page you visit twice a year would
-  // cost more attention than it returns.
-  { path: '/system', name: 'system', component: SystemView },
+  // System health is a Settings TAB, not a route of its own (operator
+  // 2026-09-02). It first shipped as /system reachable only from the health
+  // dot, which is a target you have to already suspect something to go
+  // looking for. Settings is where someone goes to ask the instance about
+  // itself. The path stays as a redirect so the dot's old link, and any
+  // bookmark from that build, still land somewhere real.
+  { path: '/system', name: 'system', redirect: () => ({ name: 'settings', query: { tab: 'system' } }) },
 
   // The old standalone paths now redirect into the Browse hub, preserving any
   // deep-link query (e.g. /posts?post_id=N → /browse?tab=posts&post_id=N). The

frontend/src/views/SettingsView.vue

@@ -14,6 +14,7 @@
       style="position: sticky; top: var(--fc-nav-h, 64px); z-index: 4;"
     >
       <v-tab value="overview">Overview</v-tab>
+      <v-tab value="system">System</v-tab>
       <v-tab value="activity">Activity</v-tab>
       <v-tab value="cleanup">Cleanup</v-tab>
       <v-tab value="maintenance">Maintenance</v-tab>
@@ -42,6 +43,13 @@
         </v-alert>
       </v-window-item>
 
+      <!-- Is every part of the stack still running (milestone 365). Sits
+           beside Activity deliberately: Activity answers "what is the queue
+           doing", this answers "is anything left to do it". -->
+      <v-window-item value="system">
+        <SystemHealthTab />
+      </v-window-item>
+
       <v-window-item value="activity">
         <SystemActivityTab @open-maintenance="tab = 'maintenance'" />
       </v-window-item>
@@ -73,18 +81,24 @@
 </template>
 
 <script setup>
-import { onMounted, onUnmounted, ref, watch } from 'vue'
+import { onMounted, onUnmounted, watch } from 'vue'
 import { useSystemStore } from '../stores/system.js'
 import SystemStatsCards from '../components/settings/SystemStatsCards.vue'
 import SystemActivitySummary from '../components/settings/SystemActivitySummary.vue'
 import SystemActivityTab from '../components/settings/SystemActivityTab.vue'
+import SystemHealthTab from '../components/settings/SystemHealthTab.vue'
 import GpuActivityPanel from '../components/settings/GpuActivityPanel.vue'
 import DownloadsActivityPanel from '../components/settings/DownloadsActivityPanel.vue'
 import MaintenancePanel from '../components/settings/MaintenancePanel.vue'
 import CleanupView from './CleanupView.vue'
+import { useTabQuery } from '../composables/useTabQuery.js'
 import { useMLStore } from '../stores/ml.js'
 
-const tab = ref('overview')
+// ?tab= sync (the same composable Browse/Subscriptions use) so a tab can be
+// linked TO — the health dot beside the brand points at ?tab=system, and the
+// old /system path redirects there.
+const VALID_TABS = ['overview', 'system', 'activity', 'cleanup', 'maintenance']
+const { tab } = useTabQuery(VALID_TABS, 'overview')
 const system = useSystemStore()
 const mlStore = useMLStore()
 

frontend/test/router.spec.js

@@ -40,6 +40,14 @@ describe('router', () => {
     expect(router.currentRoute.value.query.post_id).toBe('7')
   })
 
+  it('/system redirects into the Settings System tab', async () => {
+    // It shipped as a standalone page for one build; the health dot and any
+    // bookmark from it must still land on the surface, which is now a tab.
+    await router.push('/system')
+    expect(router.currentRoute.value.name).toBe('settings')
+    expect(router.currentRoute.value.query.tab).toBe('system')
+  })
+
   it('series-read is an immersive route', () => {
     const r = router.resolve('/series/5/read')
     expect(r.name).toBe('series-read')