feat(rag): 新增 RAG Router + 掛載到 main.py (Phase 33 ADR-067)

- rag.py: POST /index, POST /query, GET /stats 三端點
- stats 委派給 KnowledgeRAGService.get_stats()（leWOOOgo 合規）
- main.py: include_router rag_v1.router

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

apps/api/src/api/v1/rag.py

@@ -0,0 +1,102 @@
+"""
+RAG 知識庫 API Router - Phase 33
+===================================
+leWOOOgo 原則: Router 只做 HTTP 轉發，業務邏輯在 KnowledgeRAGService
+
+版本: v1.0
+建立: 2026-04-10 (台北時區)
+建立者: Claude Code (Phase 33 ADR-067)
+"""
+
+from fastapi import APIRouter, BackgroundTasks, HTTPException
+from pydantic import BaseModel
+
+from src.services.knowledge_rag_service import get_knowledge_rag_service
+
+router = APIRouter(prefix="/rag", tags=["RAG Knowledge Base"])
+
+
+class RagQueryRequest(BaseModel):
+    question: str
+    top_k: int = 5
+
+
+class RagQueryResponse(BaseModel):
+    answer: str
+    question: str
+
+
+class RagIndexResponse(BaseModel):
+    status: str
+    message: str
+
+
+@router.post("/index", response_model=RagIndexResponse, summary="觸發知識庫全量索引")
+async def trigger_index(background_tasks: BackgroundTasks) -> RagIndexResponse:
+    """
+    觸發文件向量化索引（背景執行）
+
+    索引來源：
+    - docs/runbooks/*.md
+    - docs/adr/*.md
+    - docs/LOGBOOK.md
+    - .agents/skills/*.md
+    """
+    background_tasks.add_task(_run_index)
+    return RagIndexResponse(
+        status="accepted",
+        message="索引已排程，背景執行中（nomic-embed-text @ Ollama 188）",
+    )
+
+
+@router.post("/query", response_model=RagQueryResponse, summary="語義查詢知識庫")
+async def query_rag(request: RagQueryRequest) -> RagQueryResponse:
+    """語義搜尋知識庫，用 deepseek-r1:14b 生成回答"""
+    svc = get_knowledge_rag_service()
+    answer = await svc.query(request.question, top_k=request.top_k)
+    return RagQueryResponse(answer=answer, question=request.question)
+
+
+@router.get("/stats", summary="索引統計")
+async def rag_stats() -> dict:
+    """取得知識庫索引統計（chunk 數量等）"""
+    svc = get_knowledge_rag_service()
+    return await svc.get_stats()
+
+
+# ============================================================
+# Background helper
+# ============================================================
+
+async def _run_index() -> None:
+    """背景：掃描所有文件來源並向量化"""
+    import structlog
+    from pathlib import Path
+
+    logger = structlog.get_logger(__name__)
+    svc = get_knowledge_rag_service()
+
+    sources = [
+        Path("docs/runbooks"),
+        Path("docs/adr"),
+        Path("docs"),
+        Path(".agents/skills"),
+    ]
+
+    total = 0
+    for source_dir in sources:
+        if not source_dir.exists():
+            continue
+        pattern = "*.md"
+        for md_file in source_dir.glob(pattern):
+            try:
+                count = await svc.index_document(
+                    file_path=md_file,
+                    source_type=source_dir.parts[0] if len(source_dir.parts) == 1 else source_dir.parts[1],
+                )
+                total += count
+                logger.debug("rag_indexed", file=str(md_file), chunks=count)
+            except Exception as e:
+                logger.warning("rag_index_file_failed", file=str(md_file), error=str(e))
+
+    logger.info("rag_index_complete", total_chunks=total)

apps/api/src/main.py

@@ -59,6 +59,7 @@ from src.api.v1 import (
     signoz_webhook as signoz_webhook_v1,  # Phase 21: SignOz → Telegram (ADR-037)
 )
 from src.api.v1 import drift as drift_v1  # Phase 25 P2: Config Drift Detection
+from src.api.v1 import rag as rag_v1  # Phase 33 ADR-067: RAG 知識庫
 from src.api.v1 import monitoring as monitoring_v1  # 2026-04-03: 監控工具狀態
 from src.api.v1 import stats as stats_v1  # Phase 6.5: Statistics Analytics
 from src.api.v1 import telegram as telegram_v1  # Phase 5.4: Telegram Gateway
@@ -478,6 +479,9 @@ app.include_router(
 app.include_router(
     drift_v1.router, prefix="/api/v1", tags=["Drift Detection"]
 )  # Phase 25 P2: Config Drift Detection
+app.include_router(
+    rag_v1.router, prefix="/api/v1", tags=["RAG Knowledge Base"]
+)  # Phase 33 ADR-067: RAG 知識庫
 app.include_router(
     errors_v1.router, prefix="/api/v1", tags=["Errors"]
 )  # #40: Sentry 錯誤 BFF API