init: WordFileParse docx→HTML 解析服务（含 Word EQ 域公式修复）

服务：Spring Boot 3.2 + docx4j 8.3.9，POST /api/v3/server_office_file/file/parse
      接受 .docx，返回 HTML（公式 → LaTeX，图片 → RustFS 外链）

公式支持三类来源：
- OMML（Word 2007+ 公式）      → Python omml_mathml2latex
- MathType OLE 对象            → Ruby mathtype2mathml → MathML → LaTeX
- Word EQ 域（老教辅主力）      → EqToLatexUtil（本次新增）

本次改动：
1. 新增 java-svc/.../core/EqToLatexUtil.java：
   移植自 jby backend-services office-core，EQ 语法 → LaTeX
   （\f→\dfrac、\r→\sqrt、\i→\int/\sum/\prod、\s→^{}/_{}、\b→\left\right、
     \a→array、\x→\boxed/\overline、\o\al 堆叠、圈码、化学符号、极限、连等式）
   品牌标记 JBYU* → WPU*，与采集端一致
2. CtoMathFinder：接上 EQ 分支（原为 not-ported 桩），域代码经
   EqToLatexUtil.convert 转 LaTeX 写入 eqLatexMap（WPEQNUM 占位符）
3. WordParseUtil.dealPlaceholder：EQ 的 LaTeX 同样加 \( \) 包裹
   （原先因 WPEQNUM 例外不加包裹，前端/MathJax 不渲染）

修前症状：教辅 Word 里分式/方程组/上下标整段丢失（如 {−1/3, 1} 变成 {－，1}）
修后实测：46 份教辅 2908 处 EQ 域全部还原，公式总数 2954 处、零未包裹残留

安全：application.yml（含 RustFS 密钥）不入库，提供 application.yml.example；
      OssService 的 @Value 默认密钥已清空

scripts/omml_mathml2latex/parsers/factory.py

@@ -0,0 +1,144 @@
+"""
+Input parser factory for auto-detecting and creating appropriate parsers.
+
+This module provides centralized parser creation with auto-detection
+support for determining the most appropriate parser based on input source.
+"""
+
+import os
+from typing import Union, List
+from ..core.interfaces import Parser
+
+
+class InputParserFactory:
+    """
+    Factory for creating input parsers based on source content.
+
+    This factory provides centralized parser creation with support for:
+    - Auto-detection based on file extension or content
+    - Explicit parser selection by type
+    - Clear error messages for unsupported formats
+    """
+
+    @staticmethod
+    def create_parser(source: str, parser_type: Union[str, None] = None) -> Parser:
+        """
+        Create an appropriate parser for the input source.
+
+        Args:
+            source: Input source (file path or content string)
+            parser_type: Optional explicit parser type
+                        ("docx", "omml", "mathml", or None for auto-detection)
+
+        Returns:
+            Parser instance appropriate for the source
+
+        Raises:
+            ValueError: If input format cannot be determined or is unsupported
+
+        Examples:
+            >>> factory = InputParserFactory()
+            >>> parser = factory.create_parser("equations.docx")
+            >>> isinstance(parser, DocxParser)
+            True
+
+            >>> parser = factory.create_parser("<math><mi>x</mi></math>")
+            >>> isinstance(parser, MathMLParser)
+            True
+
+            >>> parser = factory.create_parser(xml_content, parser_type="omml")
+            >>> isinstance(parser, OmmlParser)
+            True
+        """
+        # Import here to avoid circular dependencies
+        from .docx_parser import DocxParser
+        from .omml_parser import OmmlParser
+        from .mathml_parser import MathMLParser
+
+        # Explicit parser type specified
+        if parser_type:
+            parser_type = parser_type.lower()
+            if parser_type == "docx":
+                return DocxParser()
+            elif parser_type == "omml":
+                return OmmlParser()
+            elif parser_type == "mathml":
+                return MathMLParser()
+            else:
+                raise ValueError(f"Unknown parser type: {parser_type}")
+
+        # Auto-detection based on source
+        # Check file extension first (most common case)
+        if source.endswith('.docx') or (os.path.exists(source) and source.lower().endswith('.docx')):
+            return DocxParser()
+
+        # Check content for XML markers
+        # Strip whitespace for reliable detection
+        content_start = source.strip()[:200]  # Check first 200 chars
+
+        # Check for OMML namespace
+        if '<m:oMath' in content_start or '<m:oMathPara' in content_start:
+            return OmmlParser()
+
+        # Check for MathML namespace
+        if '<math' in content_start or '<mml:math' in content_start:
+            return MathMLParser()
+
+        # If it's a file path but not .docx, check file content
+        if os.path.exists(source):
+            try:
+                with open(source, 'r', encoding='utf-8') as f:
+                    file_content = f.read(500)  # Read first 500 chars
+                    if '<m:oMath' in file_content:
+                        return OmmlParser()
+                    elif '<math' in file_content or '<mml:math' in file_content:
+                        return MathMLParser()
+            except (UnicodeDecodeError, IOError):
+                # Binary file or read error - not a supported format
+                pass
+
+        # Unable to determine format
+        preview = source if len(source) <= 100 else source[:100] + "..."
+        raise ValueError(
+            f"Unable to determine input format for source: '{preview}'. "
+            f"Supported formats: .docx files, OMML XML (<m:oMath), MathML XML (<math)"
+        )
+
+    @staticmethod
+    def detect_parser_type(source: str) -> str:
+        """
+        Detect the parser type needed for the input source.
+
+        Args:
+            source: Input source (file path or content string)
+
+        Returns:
+            Parser type string ("docx", "omml", or "mathml")
+
+        Raises:
+            ValueError: If input format cannot be determined
+
+        Examples:
+            >>> factory = InputParserFactory()
+            >>> factory.detect_parser_type("equations.docx")
+            'docx'
+
+            >>> factory.detect_parser_type("<math><mi>x</mi></math>")
+            'mathml'
+        """
+        parser = InputParserFactory.create_parser(source)
+        return parser.parser_type
+
+    @staticmethod
+    def get_supported_formats() -> List[str]:
+        """
+        Get list of supported input formats.
+
+        Returns:
+            List of format identifiers that can be parsed
+        """
+        return ["docx", "omml", "mathml"]
+
+    def __repr__(self) -> str:
+        """String representation for debugging."""
+        return "InputParserFactory(docx, omml, mathml)"