feat(retry): FailedBanner + App.tsx mount (#2 v0.2.3)

src/renderer/inbox/App.tsx

@@ -10,6 +10,7 @@ import { OllamaBanner } from './components/OllamaBanner.js';
 import { RecoveryToast } from './components/RecoveryToast.js';
 import { TagUndoToast } from './components/TagUndoToast.js';
 import { ExpiryBanner } from './components/ExpiryBanner.js';
+import { FailedBanner } from './components/FailedBanner.js';
 
 export function App(): React.ReactElement {
   const {
@@ -83,6 +84,7 @@ export function App(): React.ReactElement {
               onDismiss={() => { markRecoveryDismissed(); setRecoveryDismissed(true); }}
             />
             <PendingBanner />
+            <FailedBanner />
             <ExpiryBanner />
             {tagFilter !== null && (
               <div style={{

src/renderer/inbox/components/FailedBanner.tsx

@@ -0,0 +1,32 @@
+import React from 'react';
+import { useInbox } from '../store.js';
+
+export function FailedBanner(): React.ReactElement | null {
+  const count = useInbox((s) => s.failedCount);
+  const retryAllFailed = useInbox((s) => s.retryAllFailed);
+  if (count === 0) return null;
+  return (
+    <div style={{
+      background: '#fce4e4', border: '1px solid #a33', borderRadius: 6,
+      padding: '8px 12px', margin: '8px 0', fontSize: 13,
+      display: 'flex', alignItems: 'center', gap: 8
+    }}>
+      <span style={{ flex: 1 }}>❌ AI 처리 실패 <b>{count}</b>건</span>
+      <button
+        onClick={() => {
+          retryAllFailed().catch((e) => {
+            // eslint-disable-next-line no-console
+            console.warn('retryAllFailed failed', e);
+          });
+        }}
+        style={{
+          background: '#a33', color: '#fff',
+          border: 'none', borderRadius: 4,
+          padding: '4px 12px', fontSize: 12, cursor: 'pointer'
+        }}
+      >
+        재시도
+      </button>
+    </div>
+  );
+}