feat: Knowledge Base RAG 시스템 + 채팅 LLM 개선 (Phase 0~5 완료)

- KB RAG 전체 파이프라인: 업로드, 파싱(xlsx/pdf/docx/text), 임베딩, Qdrant 인덱싱
- KB 관리 UI(14번 탭): 로그인, 문서 목록, 업로드, 삭제, 재인덱스
- OllamaController: 한글 시스템 프롬프트, plant_context.md 외부 파일화, SSE tool_start/tool_result 이벤트
- 프론트: 툴 실행 카드, KB 인용 링크, 표 자동 렌더, 추천 질문 칩
- nl2sql_worker: history_table.recorded_at 사용, tag_metadata 응답 개선
- DB: KB 테이블 5개 DDL + 시드, pgcrypto 확장

src/Web/Program.cs

@@ -3,6 +3,7 @@ using ExperionCrawler.Core.Application.Services;
 using ExperionCrawler.Infrastructure.Certificates;
 using ExperionCrawler.Infrastructure.Csv;
 using ExperionCrawler.Infrastructure.Database;
+using ExperionCrawler.Infrastructure.Kb;
 using ExperionCrawler.Infrastructure.Mcp;
 using ExperionCrawler.Infrastructure.OpcUa;
 using ExperionCrawler.Web;
@@ -119,6 +120,14 @@ builder.Services.AddSingleton<IPidGraphEventBroadcaster, PidGraphEventBroadcaste
 // ── FastTable Cleanup Service ─────────────────────────────────────────────────
 builder.Services.AddHostedService<ExperionFastCleanupService>();
 
+// ── Knowledge Base (RAG) ──────────────────────────────────────────────────────
+builder.Services.AddSingleton<KbQdrantClient>();
+builder.Services.AddSingleton<KbStorageService>();
+builder.Services.AddSingleton<KbEmbeddingClient>();
+builder.Services.AddScoped<IKbAuthService, KbAuthService>();
+builder.Services.AddHostedService<KbStartupService>();
+builder.Services.AddHostedService<KbIngestWorker>();
+
 // ── Ollama HttpClient ─────────────────────────────────────────────────────────
 builder.Services.AddHttpClient("Ollama", c =>
 {
@@ -149,6 +158,17 @@ try
     {
         var db = scope.ServiceProvider.GetRequiredService<IExperionDbService>();
         await db.InitializeAsync();
+
+        try
+        {
+            var kbAuth = scope.ServiceProvider.GetRequiredService<IKbAuthService>();
+            await kbAuth.EnsureCredentialAsync();
+        }
+        catch (Exception kbEx)
+        {
+            var lg = app.Services.GetRequiredService<ILogger<Program>>();
+            lg.LogWarning(kbEx, "[Kb] 관리자 비밀번호 초기화 실패");
+        }
     }
 }
 catch (Exception ex)