Fix config save state sync — local config now re-syncs after save

The save bar persisted forever because Zod.parse() adds defaults for
new fields, making the server config differ from local state. After
save, the sync effect now picks up the server value. Uses savingRef
to prevent overwriting local edits during the save roundtrip.

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

src/app/(admin)/admin/rounds/[roundId]/page.tsx

@@ -237,16 +237,24 @@ export default function RoundDetailPage() {
     { enabled: round?.roundType === 'FILTERING', refetchInterval: 5_000 },
   )
 
-  // Initialize config from server once on load (or when round changes externally)
+  // Initialize config from server on load; re-sync after saves
   const serverConfig = useMemo(() => (round?.configJson as Record<string, unknown>) ?? {}, [round?.configJson])
   const configInitialized = useRef(false)
-  if (round && !configInitialized.current) {
-    const roundConfig = (round.configJson as Record<string, unknown>) ?? {}
-    if (Object.keys(config).length === 0 || JSON.stringify(roundConfig) !== JSON.stringify(config)) {
-      setConfig(roundConfig)
+  const savingRef = useRef(false)
+
+  // Sync local config with server: on initial load AND whenever serverConfig
+  // changes after a save completes (so Zod-applied defaults get picked up)
+  useEffect(() => {
+    if (!round) return
+    if (!configInitialized.current) {
+      configInitialized.current = true
+      setConfig(serverConfig)
+    } else if (!savingRef.current) {
+      // Server changed (e.g. after save invalidation) — re-sync
+      setConfig(serverConfig)
     }
-    configInitialized.current = true
-  }
+  }, [serverConfig, round])
+
   const hasUnsavedConfig = useMemo(
     () => configInitialized.current && JSON.stringify(config) !== JSON.stringify(serverConfig),
     [config, serverConfig],
@@ -255,11 +263,13 @@ export default function RoundDetailPage() {
   // ── Mutations ──────────────────────────────────────────────────────────
   const updateMutation = trpc.round.update.useMutation({
     onSuccess: () => {
+      savingRef.current = false
       utils.round.getById.invalidate({ id: roundId })
       setAutosaveStatus('saved')
       setTimeout(() => setAutosaveStatus('idle'), 2000)
     },
     onError: (err) => {
+      savingRef.current = false
       setAutosaveStatus('error')
       toast.error(err.message)
     },
@@ -393,23 +403,27 @@ export default function RoundDetailPage() {
   }, [])
 
   const saveConfig = useCallback(() => {
+    savingRef.current = true
     setAutosaveStatus('saving')
     updateMutation.mutate({ id: roundId, configJson: config })
   }, [config, roundId, updateMutation])
 
   // ── Auto-save: debounce config changes and save automatically ────────
+  const configJson = JSON.stringify(config)
+  const serverJson = JSON.stringify(serverConfig)
   useEffect(() => {
     if (!configInitialized.current) return
-    if (JSON.stringify(config) === JSON.stringify(serverConfig)) return
+    if (configJson === serverJson) return
 
     const timer = setTimeout(() => {
+      savingRef.current = true
       setAutosaveStatus('saving')
       updateMutation.mutate({ id: roundId, configJson: config })
     }, 800)
 
     return () => clearTimeout(timer)
     // eslint-disable-next-line react-hooks/exhaustive-deps
-  }, [config])
+  }, [configJson])
 
   // ── Computed values ────────────────────────────────────────────────────
   const projectCount = round?._count?.projectRoundStates ?? 0