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.

src/main/ai/LocalOllamaProvider.ts

@@ -5,6 +5,14 @@ import { buildVisionPrompt } from './visionPrompt.js';
 import type { GenerateInput, GenerateOptions, HealthResult, InferenceProvider } from './InferenceProvider.js';
 import { DEFAULT_OLLAMA_ENDPOINT, DEFAULT_OLLAMA_MODEL } from '../../shared/constants.js';
 
+function classifyFetchError(e: unknown): 'network' | 'timeout' | 'dns' | 'other' {
+  const msg = ((e as Error)?.message ?? '').toLowerCase();
+  if (msg.includes('aborted') || msg.includes('timeout')) return 'timeout';
+  if (msg.includes('econnrefused') || msg.includes('econnreset')) return 'network';
+  if (msg.includes('enotfound') || msg.includes('eai_again')) return 'dns';
+  return 'other';
+}
+
 export interface LocalOllamaOptions {
   endpoint?: string;
   model?: string;
@@ -119,7 +127,8 @@ export class LocalOllamaProvider implements InferenceProvider {
       return found ? { ok: true, model: this.model }
                    : { ok: false, reason: `${this.model} not installed` };
     } catch (err) {
-      return { ok: false, reason: `unreachable: ${(err as Error).message}` };
+      const cls = classifyFetchError(err);
+      return { ok: false, reason: `unreachable:${cls}` };
     }
   }
 }