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/mspace_visitor.py

@@ -0,0 +1,194 @@
+r"""
+Visitor for <mspace> (spacing) MathML elements.
+
+The <mspace> element represents horizontal spacing in mathematical expressions.
+It uses the width attribute to specify the amount of space.
+
+Common spacing types:
+- Named spaces: thinmathspace, mediummathspace, thickmathspace
+- Negative spaces: negativethinmathspace, etc.
+- Explicit sizes: 0.1em, 1em, 2em
+
+This visitor maps MathML spacing to LaTeX spacing commands.
+"""
+
+from lxml import etree as ET
+from ..core.interfaces import Visitor, Strategy
+from ..utils import local_name as _local
+
+
+class MspaceVisitor(Visitor):
+    r"""
+    Handles <mspace> (spacing) MathML elements.
+
+    Converts spacing specifications to LaTeX spacing commands.
+
+    Examples:
+        Thin space:
+            <mspace width="thinmathspace"/>
+            → \,
+
+        Medium space:
+            <mspace width="mediummathspace"/>
+            → \:
+
+        Thick space:
+            <mspace width="thickmathspace"/>
+            → \;
+
+        Quad space:
+            <mspace width="1em"/>
+            → \quad
+
+        Qquad space:
+            <mspace width="2em"/>
+            → \qquad
+
+        Negative space:
+            <mspace width="negativethinmathspace"/>
+            → \!
+
+        Default (no width):
+            <mspace/>
+            → \, (thin space)
+    """
+
+    # Mapping from MathML spacing names to LaTeX commands
+    SPACING_MAP = {
+        # Named mathematical spaces
+        "thinmathspace": "\\,",
+        "mediummathspace": "\\:",
+        "thickmathspace": "\\;",
+        "verythinmathspace": "\\!",
+        "veryverythinmathspace": "\\!",
+
+        # Negative spaces (for fine-tuning)
+        "negativethinmathspace": "\\!",
+        "negativemediummathspace": "\\!",
+        "negativethickmathspace": "\\!",
+
+        # Explicit em-based sizes
+        "0em": "",  # No space
+        "0.1em": "\\,",
+        "0.2em": "\\:",
+        "0.3em": "\\;",
+        "0.5em": "\\;",
+        "1em": "\\quad",
+        "2em": "\\qquad",
+
+        # Alternative common values
+        "thin": "\\,",
+        "medium": "\\:",
+        "thick": "\\;",
+    }
+
+    def __init__(self, strategy: Strategy):
+        """Initialize the Mspace visitor."""
+        super().__init__(strategy)
+
+    def visit(self, node: ET.Element) -> str:
+        r"""
+        Convert <mspace> element to LaTeX spacing.
+
+        Args:
+            node: The <mspace> element to convert
+
+        Returns:
+            LaTeX spacing command (e.g., \,, \:, \;, \quad, \qquad)
+
+        Raises:
+            ValueError: If node is not an <mspace> element
+        """
+        if not self.can_handle(node):
+            raise ValueError(f"MspaceVisitor cannot handle element '{node.tag}'")
+
+        # Get width attribute
+        width = node.get("width", "")
+
+        # Handle empty width (default to thin space)
+        if not width:
+            return "\\,"
+
+        # Check if width is in our mapping
+        if width in self.SPACING_MAP:
+            return self.SPACING_MAP[width]
+
+        # Try to parse numeric width (e.g., "0.5em", "1.5em")
+        spacing_cmd = self._parse_numeric_width(width)
+        if spacing_cmd:
+            return spacing_cmd
+
+        # Default: thin space
+        return "\\,"
+
+    def _parse_numeric_width(self, width: str) -> str:
+        """
+        Parse numeric width values and convert to LaTeX spacing.
+
+        Args:
+            width: Width string (e.g., "0.5em", "1.5em")
+
+        Returns:
+            LaTeX spacing command, or empty string if cannot parse
+        """
+        # Remove whitespace
+        width = width.strip()
+
+        # Try to extract numeric value from em-based widths
+        if width.endswith("em"):
+            try:
+                value = float(width[:-2])
+
+                # Map numeric values to spacing commands
+                if value <= 0:
+                    return ""
+                elif value < 0.15:
+                    return "\\,"  # thin
+                elif value < 0.25:
+                    return "\\:"  # medium
+                elif value < 0.6:
+                    return "\\;"  # thick
+                elif value < 1.5:
+                    return "\\quad"
+                else:
+                    return "\\qquad"
+            except ValueError:
+                pass
+
+        # Try to extract numeric value from pt-based widths
+        if width.endswith("pt"):
+            try:
+                value = float(width[:-2])
+
+                # Map pt values to spacing (rough approximation)
+                # 1em ≈ 10pt in typical math fonts
+                if value <= 0:
+                    return ""
+                elif value < 2:
+                    return "\\,"
+                elif value < 4:
+                    return "\\:"
+                elif value < 6:
+                    return "\\;"
+                elif value < 12:
+                    return "\\quad"
+                else:
+                    return "\\qquad"
+            except ValueError:
+                pass
+
+        # Could not parse
+        return ""
+
+    def can_handle(self, node: ET.Element) -> bool:
+        """Check if this visitor can handle the given node."""
+        return _local(node.tag) == 'mspace'
+
+    @property
+    def element_name(self) -> str:
+        """Get the element name this visitor handles."""
+        return 'mspace'
+
+    def __repr__(self) -> str:
+        """String representation for debugging."""
+        return f"MspaceVisitor(strategy={self.strategy.name})"