fix(rag): fix pdfplumber concurrency issue and add debug logging

The pdfplumber parser now uses a global lock to prevent concurrent access issues during PDF image rendering. Additionally, added a warning log to trace knowledge retrieval results for debugging purposes. The syntax fix in knowledge node's match case ensures correct pattern matching behavior.

BREAKING CHANGE: The pdfplumber parser now requires LOCK_KEY_pdfplumber to be defined in sys.modules for thread safety.

Closes #841

api/app/core/rag/deepdoc/parser/mineru_parser.py

@@ -292,9 +292,10 @@ class MinerUParser(RAGPdfParser):
         self.page_from = page_from
         self.page_to = page_to
         try:
-            with pdfplumber.open(fnm) if isinstance(fnm, (str, PathLike)) else pdfplumber.open(BytesIO(fnm)) as pdf:
-                self.pdf = pdf
-                self.page_images = [p.to_image(resolution=72 * zoomin, antialias=True).original for _, p in enumerate(self.pdf.pages[page_from:page_to])]
+            with sys.modules[LOCK_KEY_pdfplumber]:  # ← 加这一行，获取全局锁
+                with pdfplumber.open(fnm) if isinstance(fnm, (str, PathLike)) else pdfplumber.open(BytesIO(fnm)) as pdf:
+                    self.pdf = pdf
+                    self.page_images = [p.to_image(resolution=72 * zoomin, antialias=True).original for _, p in enumerate(self.pdf.pages[page_from:page_to])]
         except Exception as e:
             self.page_images = None
             self.total_page = 0

api/app/core/workflow/nodes/knowledge/node.py

@@ -233,7 +233,7 @@ class KnowledgeRetrievalNode(BaseNode):
                         }
                     )
                 )
-            case RetrieveType.HYBRID | RetrieveType.Graph:
+            case (RetrieveType.HYBRID, RetrieveType.Graph):
                 rs1_task = asyncio.to_thread(
                     vector_service.search_by_vector, **{
                         "query": query,