feat(transit): 支持Markdown图片转Word图片段落

- 新增 transit/images.py 模块处理图片解析和插入逻辑
- 实现 `<img>` 标签解析为独立图片段落
- 添加图片尺寸检测和自适应缩放功能（超出页面宽度时自动缩放）
- 支持图标题居中显示和图片居中对齐
- 优化 body_to_paragraphs 函数，添加图片处理逻辑
- 更新 README.md 使用说明，添加模板文件要求说明

BREAKING CHANGE: 图片处理方式变更，需要包含 sample.docx 模板文件

transit/body.py

@@ -7,9 +7,12 @@ Markdown 正文 → Word 段落转换。
 
 import re
 from copy import deepcopy
+
 from docx import Document
 from docx.oxml.ns import qn
 
+from .images import make_image_paragraph, is_figure_caption, insert_image_paragraphs
+
 _PAT_HEADING = re.compile(r"^(#{1,6})\s+(.+)$", re.MULTILINE)
 
 
@@ -33,17 +36,28 @@ def body_to_paragraphs(
     paragraphs: list[dict] = []
     last_end = 0
 
+    def _add_block(block: str) -> None:
+        block = block.strip()
+        if not block:
+            return
+        # 图片段落
+        img = make_image_paragraph(block)
+        if img:
+            paragraphs.append(img)
+            return
+        # 跳过紧跟在图片后的重复图标题
+        if paragraphs and paragraphs[-1].get("type") == "image" and is_figure_caption(block):
+            return
+        # 普通正文段落
+        paragraphs.append({"text": block, "level": 0, "style": body_style})
+
     for m in _PAT_HEADING.finditer(md_text):
         # 标题前的普通文本
         if m.start() > last_end:
             pre = md_text[last_end : m.start()].strip()
             if pre:
                 for block in re.split(r"\n\s*\n", pre):
-                    block = block.strip()
-                    if block:
-                        paragraphs.append(
-                            {"text": block, "level": 0, "style": body_style}
-                        )
+                    _add_block(block)
 
         level = len(m.group(1)) + level_offset
         heading_text = m.group(2).strip()
@@ -56,11 +70,7 @@ def body_to_paragraphs(
     tail = md_text[last_end:].strip()
     if tail:
         for block in re.split(r"\n\s*\n", tail):
-            block = block.strip()
-            if block:
-                paragraphs.append(
-                    {"text": block, "level": 0, "style": body_style}
-                )
+            _add_block(block)
 
     return paragraphs
 
@@ -94,31 +104,36 @@ def replace_placeholder(
             parent.remove(para._element)
 
             for pd_data in reversed(paragraphs):
-                new_p = doc.add_paragraph(pd_data["text"])
-                style_name = pd_data["style"]
+                if pd_data.get("type") == "image":
+                    insert_image_paragraphs(
+                        doc, [pd_data], idx=idx, parent=parent
+                    )
+                else:
+                    new_p = doc.add_paragraph(pd_data["text"])
+                    style_name = pd_data["style"]
 
-                # 尝试应用样式，逐步降级
-                applied = _apply_style(new_p, doc, style_name)
-                if not applied and style_name.startswith("Heading"):
-                    new_p.style = doc.styles["Normal"]
-                elif not applied:
-                    if placeholder_style:
-                        _apply_style(new_p, doc, placeholder_style)
-                    if new_p.style.name == "Normal" and placeholder_style:
-                        new_p.style = doc.styles[placeholder_style]
+                    # 尝试应用样式，逐步降级
+                    applied = _apply_style(new_p, doc, style_name)
+                    if not applied and style_name.startswith("Heading"):
+                        new_p.style = doc.styles["Normal"]
+                    elif not applied:
+                        if placeholder_style:
+                            _apply_style(new_p, doc, placeholder_style)
+                        if new_p.style.name == "Normal" and placeholder_style:
+                            new_p.style = doc.styles[placeholder_style]
 
-                # 继承原段落的编号属性（自动编号）
-                if numPr is not None:
-                    new_pPr = new_p._element.find(qn("w:pPr"))
-                    if new_pPr is None:
-                        new_pPr = new_p._element.makeelement(qn("w:pPr"), {})
-                        new_p._element.insert(0, new_pPr)
-                    existing = new_pPr.find(qn("w:numPr"))
-                    if existing is not None:
-                        new_pPr.remove(existing)
-                    new_pPr.append(deepcopy(numPr))
+                    # 继承原段落的编号属性（自动编号）
+                    if numPr is not None:
+                        new_pPr = new_p._element.find(qn("w:pPr"))
+                        if new_pPr is None:
+                            new_pPr = new_p._element.makeelement(qn("w:pPr"), {})
+                            new_p._element.insert(0, new_pPr)
+                        existing = new_pPr.find(qn("w:numPr"))
+                        if existing is not None:
+                            new_pPr.remove(existing)
+                        new_pPr.append(deepcopy(numPr))
 
-                parent.insert(idx, new_p._element)
+                    parent.insert(idx, new_p._element)
             break
 
     if not placeholder_found: