fix(react): remove four setState-in-effect cascades flagged by react-hooks v5

The new react-hooks lint rule "Calling setState synchronously within an
effect can trigger cascading renders" flagged real anti-patterns in
four spots. Refactored each per the rule's intent (derive during render,
or use useSyncExternalStore for external subscriptions).

1. hooks/useMediaQuery.ts — replaced the useState + useEffect pair with
   useSyncExternalStore. That's the canonical React hook for
   subscribing to external stores (matchMedia in this case) without
   mirroring into local state via an effect. Snapshot/getServerSnapshot
   pair preserves the SSR-safe behaviour.

2. components/network/nodes/DeviceNode.tsx — the prop-sync useEffect
   that copied nodeData.label into labelValue was redundant.
   labelValue is the EDIT BUFFER; while not editing, the displayed
   span now reads nodeData.label directly. The buffer is initialized
   only when an edit session starts (onDoubleClick).

3. components/network/nodes/GroupNode.tsx — same pattern, same fix.

4. components/dashboard/TicketQueue.tsx — the
   setTickets([]) + setLoading(true) + fetchTickets() chain in the
   effect was the cascade. Pushed those writes inside fetchTickets
   (after the function boundary, so they batch with the eventual
   setTickets(result)). Added a request-id ref so a slow first
   response can't overwrite a fast second one.

Frontend lint: 20 errors → 0 errors. tsc -b clean.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

frontend/src/hooks/useMediaQuery.ts

@@ -1,27 +1,28 @@
-import { useEffect, useState } from 'react'
+import { useSyncExternalStore } from 'react'
 
 /**
  * SSR-safe CSS media-query hook. Returns the current match boolean and
  * re-renders on viewport changes. Used by /pilot to swap the task lane
  * between side panel (≥1200px) and bottom drawer (<1200px) per Phase 7.
+ *
+ * Implemented with useSyncExternalStore to subscribe to the MediaQueryList
+ * without an effect — this is the React-idiomatic shape for external-state
+ * subscriptions and avoids the setState-in-effect cascade lint rule.
  */
 export function useMediaQuery(query: string): boolean {
-  const [matches, setMatches] = useState<boolean>(() => {
-    if (typeof window === 'undefined') return false
-    return window.matchMedia(query).matches
-  })
-
-  useEffect(() => {
-    if (typeof window === 'undefined') return
-    const mql = window.matchMedia(query)
-    const handler = (e: MediaQueryListEvent) => setMatches(e.matches)
-    // Sync once on mount in case state drifted between render and effect.
-    setMatches(mql.matches)
-    mql.addEventListener('change', handler)
-    return () => mql.removeEventListener('change', handler)
-  }, [query])
-
-  return matches
+  return useSyncExternalStore(
+    (onChange) => {
+      if (typeof window === 'undefined') return () => {}
+      const mql = window.matchMedia(query)
+      mql.addEventListener('change', onChange)
+      return () => mql.removeEventListener('change', onChange)
+    },
+    () => {
+      if (typeof window === 'undefined') return false
+      return window.matchMedia(query).matches
+    },
+    () => false, // server snapshot — match initial false
+  )
 }
 
 export default useMediaQuery