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/visitors/mglyph_visitor.py

@@ -0,0 +1,105 @@
+r"""
+Visitor for <mglyph> (custom glyph) MathML elements.
+
+The <mglyph> element is used to display non-standard symbols or images
+within mathematical expressions. It references external images via the
+'src' attribute or font glyphs via 'fontfamily' and 'index' attributes.
+
+In LaTeX conversion, mglyph is converted to text representations or
+fallback Unicode characters when available. For image-based glyphs,
+alt text is used if provided.
+"""
+
+from lxml import etree as ET
+from ..core.interfaces import Visitor, Strategy
+from ..utils import local_name as _local, text_content as _text_content
+
+
+class MglyphVisitor(Visitor):
+    r"""
+    Handles <mglyph> (custom glyph) MathML elements.
+
+    Converts custom glyphs to LaTeX text or fallback Unicode. Since LaTeX
+    doesn't support arbitrary image references, we use alt text or text
+    content as fallback.
+
+    Examples:
+        Glyph with alt text:
+            <mglyph src="myGlyph.png" alt="custom symbol"/>
+            → \text{custom symbol}
+
+        Glyph with font reference:
+            <mglyph fontfamily="MyFont" index="42" alt="α"/>
+            → \text{α}
+
+        Glyph without alt (uses src filename):
+            <mglyph src="alpha.png"/>
+            → \text{alpha}
+
+        Glyph with width/height (ignored in LaTeX):
+            <mglyph src="beta.png" width="2em" height="2em" alt="β"/>
+            → \text{β}
+
+    Note:
+        LaTeX doesn't support external image references in math mode,
+        so we convert to text representations using alt attribute or
+        derive from src filename.
+    """
+
+    def __init__(self, strategy: Strategy):
+        """Initialize the Mglyph visitor."""
+        super().__init__(strategy)
+
+    def visit(self, node: ET.Element) -> str:
+        r"""
+        Convert <mglyph> element to LaTeX text.
+
+        Args:
+            node: The <mglyph> element to convert
+
+        Returns:
+            LaTeX string with \text{...} fallback
+
+        Raises:
+            ValueError: If node is not a <mglyph> element
+        """
+        if not self.can_handle(node):
+            raise ValueError(f"MglyphVisitor cannot handle element '{node.tag}'")
+
+        # Try to get alt text (primary fallback)
+        alt_text = node.get("alt", "")
+
+        if alt_text:
+            # Use alt text if provided
+            return f"\\text{{{alt_text}}}"
+
+        # Fallback: try to derive from src attribute
+        src = node.get("src", "")
+        if src:
+            # Extract filename without extension as fallback
+            import os
+            filename = os.path.splitext(os.path.basename(src))[0]
+            if filename:
+                return f"\\text{{{filename}}}"
+
+        # Last resort: fontfamily reference or empty
+        fontfamily = node.get("fontfamily", "")
+        if fontfamily:
+            # Can't do much with font references in LaTeX
+            return f"\\text{{{fontfamily}}}"
+
+        # Completely empty - render as empty
+        return ""
+
+    def can_handle(self, node: ET.Element) -> bool:
+        """Check if this visitor can handle the given node."""
+        return _local(node.tag) == 'mglyph'
+
+    @property
+    def element_name(self) -> str:
+        """Get the element name this visitor handles."""
+        return 'mglyph'
+
+    def __repr__(self) -> str:
+        """String representation for debugging."""
+        return f"MglyphVisitor(strategy={self.strategy.name})"