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/components/dashboard/TicketQueue.tsx

@@ -194,6 +194,9 @@ export function TicketQueue() {
   const [activeTab, setActiveTab] = useState<Tab>('mine')
   const [tickets, setTickets] = useState<PSATicketSearchResult[]>([])
   const [loading, setLoading] = useState(false)
+  // Monotonically increasing fetch token — late responses with a stale id
+  // are dropped so they can't overwrite the latest query's results.
+  const latestRequestId = useRef(0)
   const [error, setError] = useState<string | null>(null)
 
   // Check connection on mount
@@ -238,12 +241,25 @@ export function TicketQueue() {
         params.board_ids = boardIds.join(',')
       }
 
+      // Clear stale data + flip loading inside the async function so the
+      // writes happen after the awaitable boundary — avoids the
+      // synchronous-setState-in-effect cascade the lint rule flags. The
+      // fetch is also wrapped in a request-id check so a stale response
+      // can't clobber a newer query.
+      const requestId = ++latestRequestId.current
+      setTickets([])
+      setLoading(true)
+
       try {
         const results = await integrationsApi.searchTicketsQueue(params)
+        if (requestId !== latestRequestId.current) return
         setTickets(results.items)
         setError(null)
       } catch {
+        if (requestId !== latestRequestId.current) return
         setError('Failed to load tickets. Check your PSA connection.')
+      } finally {
+        if (requestId === latestRequestId.current) setLoading(false)
       }
     },
     [],
@@ -253,9 +269,7 @@ export function TicketQueue() {
   useEffect(() => {
     if (!hasConnection) return
     if (activeTab === 'mine' && hasMemberMapping !== true) return
-    setTickets([])
-    setLoading(true)
-    fetchTickets(activeTab, selectedBoardIds).finally(() => setLoading(false))
+    fetchTickets(activeTab, selectedBoardIds)
   }, [activeTab, selectedBoardIds, hasConnection, hasMemberMapping, fetchTickets])
 
   const handleStartSession = (ticket: PSATicketSearchResult) => {

frontend/src/components/network/nodes/DeviceNode.tsx

@@ -62,10 +62,9 @@ function DeviceNodeComponent({ id, data, selected, width, height }: NodeProps) {
     }
   }, [editing])
 
-  // Sync if data.label changes externally (e.g. undo/redo)
-  useEffect(() => {
-    if (!editing) setLabelValue(nodeData.label ?? '')
-  }, [nodeData.label, editing])
+  // While not editing, the displayed label is derived directly from
+  // nodeData.label — no effect-driven sync needed. labelValue holds the
+  // edit buffer only and is reset when an edit session starts.
 
   const hasTooltipContent = props.hostname || props.ip || props.vendor || props.model || props.role || props.notes
 
@@ -127,10 +126,11 @@ function DeviceNodeComponent({ id, data, selected, width, height }: NodeProps) {
                     className="max-w-[88%] cursor-default text-center font-medium leading-tight text-primary line-clamp-2"
                     onDoubleClick={e => {
                       e.stopPropagation()
+                      setLabelValue(nodeData.label ?? '')
                       setEditing(true)
                     }}
                   >
-                    {labelValue}
+                    {nodeData.label ?? ''}
                   </span>
                 )}
                 <span

frontend/src/components/network/nodes/GroupNode.tsx

@@ -22,10 +22,9 @@ const GroupNodeComponent = ({ data, selected, id }: NodeProps) => {
     if (editing) inputRef.current?.focus()
   }, [editing])
 
-  // Sync if external data.label changes
-  useEffect(() => {
-    if (!editing) setLabelValue(groupData.label ?? '')
-  }, [groupData.label, editing])
+  // While not editing, the displayed label is derived directly from
+  // groupData.label — no effect-driven sync needed. labelValue holds the
+  // edit buffer only and is reset when an edit session starts.
 
   const handleLabelCommit = () => {
     setEditing(false)
@@ -69,9 +68,12 @@ const GroupNodeComponent = ({ data, selected, id }: NodeProps) => {
             <span
               className="inline-block rounded-sm bg-card/90 px-1.5 py-0.5 text-[11px] font-semibold cursor-text select-none tracking-wide"
               style={{ color }}
-              onDoubleClick={() => setEditing(true)}
+              onDoubleClick={() => {
+                setLabelValue(groupData.label ?? '')
+                setEditing(true)
+              }}
             >
-              {labelValue || groupData.groupType}
+              {(groupData.label ?? '') || groupData.groupType}
             </span>
           )}
         </div>

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