Refa: only support MinerU-API now (#11977)

### What problem does this PR solve?

Only support MinerU-API now, still need to complete frontend for
pipeline to allow the configuration of MinerU options.

### Type of change

- [x] Refactoring

rag/llm/ocr_model.py

@@ -16,7 +16,7 @@
 import json
 import logging
 import os
-from typing import Any, Optional, Tuple
+from typing import Any, Optional
 
 from deepdoc.parser.mineru_parser import MinerUParser
 
@@ -25,7 +25,7 @@ class Base:
     def __init__(self, key: str | dict, model_name: str, **kwargs):
         self.model_name = model_name
 
-    def parse_pdf(self, filepath: str, binary=None, **kwargs) -> Tuple[Any, Any]:
+    def parse_pdf(self, filepath: str, binary=None, **kwargs) -> tuple[Any, Any]:
         raise NotImplementedError("Please implement parse_pdf!")
 
 
@@ -56,21 +56,22 @@ class MinerUOcrModel(Base, MinerUParser):
         self.mineru_backend = _resolve_config("mineru_backend", "MINERU_BACKEND", "pipeline")
         self.mineru_server_url = _resolve_config("mineru_server_url", "MINERU_SERVER_URL", "")
         self.mineru_delete_output = bool(int(_resolve_config("mineru_delete_output", "MINERU_DELETE_OUTPUT", 1)))
-        self.mineru_executable = os.environ.get("MINERU_EXECUTABLE", "mineru")
 
-        logging.info(f"Parsed MinerU config: {config}")
+        logging.info(
+            f"Parsed MinerU config: backend={self.mineru_backend} api={self.mineru_api} server_url={self.mineru_server_url} output_dir={self.mineru_output_dir} delete_output={self.mineru_delete_output}"
+        )
 
-        MinerUParser.__init__(self, mineru_path=self.mineru_executable, mineru_api=self.mineru_api, mineru_server_url=self.mineru_server_url)
+        MinerUParser.__init__(self, mineru_api=self.mineru_api, mineru_server_url=self.mineru_server_url)
 
-    def check_available(self, backend: Optional[str] = None, server_url: Optional[str] = None) -> Tuple[bool, str]:
+    def check_available(self, backend: Optional[str] = None, server_url: Optional[str] = None) -> tuple[bool, str]:
         backend = backend or self.mineru_backend
         server_url = server_url or self.mineru_server_url
         return self.check_installation(backend=backend, server_url=server_url)
 
-    def parse_pdf(self, filepath: str, binary=None, callback=None, parse_method: str = "raw",**kwargs):
+    def parse_pdf(self, filepath: str, binary=None, callback=None, parse_method: str = "raw", **kwargs):
         ok, reason = self.check_available()
         if not ok:
-            raise RuntimeError(f"MinerU not found or server not accessible: {reason}. Please install it via: pip install -U 'mineru[core]'.")
+            raise RuntimeError(f"MinerU server not accessible: {reason}")
 
         sections, tables = MinerUParser.parse_pdf(
             self,