fix: Cell Identity changes now show Configuration changes pending banner

DraftConfig dirty state (set when any Cell Identity field changes) was
tracked in refs but never checked by the banner, which only looked at
backend pending state. Cell name changes in pic_ngo mode intentionally
block auto-save (to prevent premature DDNS re-registration), so the
backend never marked pending and the banner never appeared.

Fix: show the banner when hasDirty() is true in addition to backend
pending. Add clearAllDirty() to DraftConfigContext so Cancel immediately
clears frontend dirty state without waiting for the next 5-second poll.

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

webui/src/App.jsx

@@ -188,7 +188,7 @@ function AppCore() {
   const [applyStatus, setApplyStatus] = useState(null); // null | 'saving' | 'restarting' | 'done' | 'timeout' | 'error'
   const [applyError, setApplyError] = useState('');
 
-  const { flushAll, hasDirty } = useDraftConfig();
+  const { flushAll, hasDirty, clearAllDirty } = useDraftConfig();
 
   const handleApply = useCallback(async () => {
     setApplyError('');
@@ -231,10 +231,11 @@ function AppCore() {
   }, [flushAll, hasDirty]);
 
   const handleCancel = useCallback(async () => {
+    clearAllDirty();
     await cellAPI.cancelPending();
     setPending({ needs_restart: false, changes: [] });
     window.dispatchEvent(new CustomEvent('pic-config-discarded'));
-  }, []);
+  }, [clearAllDirty]);
 
   const [activeServiceChildren, setActiveServiceChildren] = useState([]);
 
@@ -327,7 +328,7 @@ function AppCore() {
                       </div>
                     )}
 
-                    {isOnline && pending.needs_restart && !applyStatus && (
+                    {isOnline && (pending.needs_restart || hasDirty()) && !applyStatus && (
                       <PendingRestartBanner pending={pending} onApply={handleApply} onCancel={handleCancel} />
                     )}
 

webui/src/contexts/DraftConfigContext.jsx

@@ -25,8 +25,12 @@ export function DraftConfigProvider({ children }) {
     await Promise.all(flushers.map(fn => fn()));
   }, []);
 
+  const clearAllDirty = useCallback(() => {
+    hasDirtyRef.current = {};
+  }, []);
+
   return (
-    <DraftConfigContext.Provider value={{ registerFlusher, setDirty, hasDirty, flushAll }}>
+    <DraftConfigContext.Provider value={{ registerFlusher, setDirty, hasDirty, flushAll, clearAllDirty }}>
       {children}
     </DraftConfigContext.Provider>
   );