feat(diag): log resolved Ollama endpoint + surface health reason in banner

When the OllamaBanner appears, it was generic enough that the user
couldn't tell whether the env var was missing, the LAN host was
unreachable, the model was uninstalled, or DNS was failing. Log the
resolved endpoint at startup with a `fromEnv` flag so we can confirm
INKLING_OLLAMA_ENDPOINT was actually read, and render the underlying
health-check reason as a small subtitle under the banner copy.

The user-facing primary message still avoids the forbidden tone words
("실패"/"끊김"/"연속 실패"); the diagnostic line is technical and only
appears when status.reason is set.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

src/main/index.ts

@@ -34,9 +34,12 @@ app.whenReady().then(async () => {
   const continuity = new ContinuityService(db);
   const intent = new IntentService(repo);
 
-  const provider = new LocalOllamaProvider({
-    endpoint: process.env.INKLING_OLLAMA_ENDPOINT
+  const resolvedEndpoint = process.env.INKLING_OLLAMA_ENDPOINT ?? 'http://localhost:11434';
+  logger.info('ai.endpoint', {
+    endpoint: resolvedEndpoint,
+    fromEnv: process.env.INKLING_OLLAMA_ENDPOINT !== undefined
   });
+  const provider = new LocalOllamaProvider({ endpoint: resolvedEndpoint });
   const health = new HealthChecker(provider);
   void health.runOnce().then((h) => logger.info('ai.health', { ...h } as Record<string, unknown>));
 

src/renderer/inbox/components/OllamaBanner.tsx

@@ -9,8 +9,13 @@ export function OllamaBanner(): React.ReactElement | null {
     ? '`ollama pull gemma4:e4b` 실행 후 앱을 재시작해주세요.'
     : 'Inkling 정리가 잠시 멈췄습니다. Ollama를 실행해주세요.';
   return (
-    <div className="banner warn">
+    <div className="banner warn" style={{ flexDirection: 'column', alignItems: 'flex-start' }}>
       <span>⚠ {message}</span>
+      {status.reason ? (
+        <span style={{ fontSize: 11, opacity: 0.7, marginTop: 4 }}>
+          진단: {status.reason}
+        </span>
+      ) : null}
     </div>
   );
 }