fix(v032): healthCheck reason PII 마스킹 (#39)

err.message 안에 LAN endpoint URL (예: 192.168.x.x:11434) 이 포함될 수
있어 telemetry 파일에 PII 우회 노출. v0.2.3.1 in-app endpoint UI 가 LAN
사용을 흔하게 만들어 노출 경로 확대.

classifyFetchError 로 error class 분류 (network/timeout/dns/other) 후
reason: 'unreachable:{class}' 형태만 emit. host/IP 노출 0.

tests/unit/LocalOllamaProvider.test.ts

@@ -110,6 +110,44 @@ describe('LocalOllamaProvider', () => {
     expect(provider.name).toBe('local-ollama/gemma4:26b');
   });
 
+  describe('healthCheck PII reason masking', () => {
+    it('classifies ECONNREFUSED as network', async () => {
+      mock.get('http://192.168.1.5:11434').intercept({ path: '/api/tags', method: 'GET' })
+        .replyWithError(new Error('connect ECONNREFUSED 192.168.1.5:11434'));
+      const provider = new LocalOllamaProvider({ endpoint: 'http://192.168.1.5:11434' });
+      const h = await provider.healthCheck();
+      expect(h.ok).toBe(false);
+      expect(h.reason).toBe('unreachable:network');
+      expect(h.reason).not.toContain('192.168.1.5');
+    });
+
+    it('classifies AbortError/timeout as timeout', async () => {
+      mock.get('http://localhost:11434').intercept({ path: '/api/tags', method: 'GET' })
+        .replyWithError(new Error('The operation was aborted due to timeout'));
+      const h = await new LocalOllamaProvider().healthCheck();
+      expect(h.ok).toBe(false);
+      expect(h.reason).toBe('unreachable:timeout');
+    });
+
+    it('classifies ENOTFOUND as dns', async () => {
+      mock.get('http://nonexistent.local:11434').intercept({ path: '/api/tags', method: 'GET' })
+        .replyWithError(new Error('getaddrinfo ENOTFOUND nonexistent.local'));
+      const provider = new LocalOllamaProvider({ endpoint: 'http://nonexistent.local:11434' });
+      const h = await provider.healthCheck();
+      expect(h.ok).toBe(false);
+      expect(h.reason).toBe('unreachable:dns');
+      expect(h.reason).not.toContain('nonexistent.local');
+    });
+
+    it('falls back to other for unknown errors', async () => {
+      mock.get('http://localhost:11434').intercept({ path: '/api/tags', method: 'GET' })
+        .replyWithError(new Error('something weird happened'));
+      const h = await new LocalOllamaProvider().healthCheck();
+      expect(h.ok).toBe(false);
+      expect(h.reason).toBe('unreachable:other');
+    });
+  });
+
   describe('vision path (v0.3.1 Cut F)', () => {
     it('visionModel + images → body.images + model=visionModel + buildVisionPrompt', async () => {
       let capturedBody: string = '';