feat: 完善 AI-Core 文档解析器

- 添加多种文档解析器 (PDF, Word, Excel, Markdown 等)
- 添加基础解析器和链式解析器
- 添加存储和注册机制
- 添加 gRPC 服务实现

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

ai-core/parser/parser.py

@@ -0,0 +1,88 @@
+import logging
+from typing import Any, Optional
+
+from docreader.models.document import Document
+from docreader.parser.registry import registry
+from docreader.parser.web_parser import WebParser
+
+logger = logging.getLogger(__name__)
+
+
+class Parser:
+    """Document parser facade (lightweight version).
+
+    Converts files/URLs to markdown + image references.
+    No chunking, no storage, no OCR, no VLM.
+    """
+
+    def __init__(self):
+        self.registry = registry
+        logger.info(
+            "Parser initialized with engines: %s",
+            ", ".join(self.registry.get_engine_names()),
+        )
+
+    def parse_file(
+        self,
+        file_name: str,
+        file_type: str,
+        content: bytes,
+        parser_engine: Optional[str] = None,
+        engine_overrides: Optional[dict[str, Any]] = None,
+        vlm_config: Optional[dict[str, Any]] = None,
+    ) -> Document:
+        """Parse file content to markdown."""
+        engine = parser_engine or ""
+        overrides = engine_overrides or {}
+        logger.info(
+            "Parsing file: %s, type: %s, engine: %s, vlm_enabled: %s",
+            file_name,
+            file_type,
+            engine or "builtin",
+            vlm_config.get("enabled") if vlm_config else False,
+        )
+
+        # 如果有 VLM 配置，添加到 overrides 中
+        if vlm_config and vlm_config.get("enabled"):
+            overrides["vlm_config"] = vlm_config
+
+        cls = self.registry.get_parser_class(engine, file_type)
+        logger.info(
+            "Creating %s parser instance for %s file",
+            cls.__name__,
+            file_type,
+        )
+        parser = cls(
+            file_name=file_name,
+            file_type=file_type,
+            **overrides,
+        )
+
+        logger.info("Starting to parse file content, size: %d bytes", len(content))
+        result = parser.parse(content)
+
+        if not result.content:
+            logger.warning("Parser returned empty content for file: %s", file_name)
+        logger.info(
+            "Parsed file %s, content length=%d", file_name, len(result.content)
+        )
+        return result
+
+    def parse_url(
+        self,
+        url: str,
+        title: str,
+        parser_engine: Optional[str] = None,
+        engine_overrides: Optional[dict[str, Any]] = None,
+    ) -> Document:
+        """Parse content from a URL to markdown."""
+        logger.info("Parsing URL: %s, title: %s", url, title)
+
+        parser = WebParser(title=title)
+        logger.info("Starting to parse URL content")
+        result = parser.parse(url.encode())
+
+        if not result.content:
+            logger.warning("Parser returned empty content for url: %s", url)
+        logger.info("Parsed url %s, content length=%d", url, len(result.content))
+        return result