feat(explorer): mission-control resilience, ops token labels, and CI validate

Add SSE reconnect with backoff, fallback REST polling, visibility-aware refresh,
extended token-list labels on operations pages, validate-on-pr workflow, and smoke coverage.

Co-authored-by: Cursor <cursoragent@cursor.com>

frontend/src/components/home/HomePage.tsx

@@ -32,6 +32,7 @@ import {
   HOME_PRICE_FEED_REFRESH_MS,
   resolveHomePriceFeedAddresses,
 } from '@/utils/featuredTokens'
+import { createVisibilityAwarePoller } from '@/utils/visibilityRefresh'
 
 type HomeStats = ExplorerStats
 
@@ -180,14 +181,11 @@ export default function Home({
   }, [chainId])
 
   useEffect(() => {
-    loadDashboard()
-    const timer = window.setInterval(() => {
-      void loadDashboard()
-    }, HOME_DASHBOARD_REFRESH_MS)
-
-    return () => {
-      window.clearInterval(timer)
-    }
+    void loadDashboard()
+    return createVisibilityAwarePoller({
+      intervalMs: HOME_DASHBOARD_REFRESH_MS,
+      task: loadDashboard,
+    })
   }, [loadDashboard])
 
   useEffect(() => {
@@ -210,7 +208,6 @@ export default function Home({
 
   useEffect(() => {
     let cancelled = false
-    let timer: ReturnType<typeof setTimeout> | null = null
 
     const refreshFeaturedPrices = async () => {
       try {
@@ -221,20 +218,18 @@ export default function Home({
         if (!cancelled && process.env.NODE_ENV !== 'production') {
           console.warn('Failed to load featured token prices:', error)
         }
-      } finally {
-        if (!cancelled) {
-          timer = setTimeout(() => {
-            void refreshFeaturedPrices()
-          }, HOME_PRICE_FEED_REFRESH_MS)
-        }
       }
     }
 
     void refreshFeaturedPrices()
+    const stop = createVisibilityAwarePoller({
+      intervalMs: HOME_PRICE_FEED_REFRESH_MS,
+      task: refreshFeaturedPrices,
+    })
 
     return () => {
       cancelled = true
-      if (timer) clearTimeout(timer)
+      stop()
     }
   }, [loadFeaturedPrices])
 
@@ -307,6 +302,31 @@ export default function Home({
     }
   }, [])
 
+  useEffect(() => {
+    if (relayFeedState !== 'fallback') return
+
+    let cancelled = false
+
+    const refreshSnapshot = async () => {
+      try {
+        const status = await missionControlApi.getBridgeStatus()
+        if (!cancelled) {
+          setBridgeStatus(status)
+          setRelaySummary(summarizeMissionControlRelay(status))
+        }
+      } catch (error) {
+        if (!cancelled && process.env.NODE_ENV !== 'production') {
+          console.warn('Failed to refresh mission control snapshot:', error)
+        }
+      }
+    }
+
+    return createVisibilityAwarePoller({
+      intervalMs: HOME_DASHBOARD_REFRESH_MS,
+      task: refreshSnapshot,
+    })
+  }, [relayFeedState])
+
   const relayToneClasses =
     relaySummary?.tone === 'danger'
       ? 'border-red-200 bg-red-50 text-red-900 dark:border-red-900/60 dark:bg-red-950/40 dark:text-red-100'