fix(knowledge): 路由改為無尾斜線避免 307 redirect

GET "" 代替 "/" 讓 /api/v1/knowledge 直接回應，
不再觸發 FastAPI trailing-slash 307 重導向。
此修正與 ProxyHeadersMiddleware 雙重保障。

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

apps/api/src/api/v1/knowledge.py

@@ -36,7 +36,7 @@ router = APIRouter(prefix="/knowledge", tags=["Knowledge Base"])
 # Endpoints
 # =============================================================================
 
-@router.get("/", response_model=KnowledgeListResponse)
+@router.get("", response_model=KnowledgeListResponse)
 async def list_entries(
     category: str | None = Query(None, description="篩選分類"),
     entry_type: EntryType | None = Query(None, description="篩選類型"),
@@ -85,7 +85,7 @@ async def get_entry(entry_id: str) -> KnowledgeEntry:
     return entry
 
 
-@router.post("/", response_model=KnowledgeEntry, status_code=201)
+@router.post("", response_model=KnowledgeEntry, status_code=201)
 async def create_entry(data: KnowledgeEntryCreate) -> KnowledgeEntry:
     """建立新知識條目"""
     service = get_knowledge_service()