♻️ refactor(UI): 重构UI渲染服务为组件化分层架构 (#2025)

* ♻️ refactor(UI): 重构UI渲染服务为组件化分层架构

♻️ **架构重构**
- UI渲染服务重构为组件化分层架构
- 解耦主题管理、HTML生成、截图功能

✨ **新增功能**
- `zhenxun.ui` 统一入口，提供 `render`、`markdown`、`vstack` 等API
- `RenderableComponent` 基类和渲染协议抽象
- 新增主题管理器和截图引擎模块

⚙️ **配置优化**
- UI配置迁移至 `superuser/ui_manager.py`
- 新增"重载UI主题"管理指令

🔧 **性能改进**
- 优化渲染缓存，支持组件级透明缓存
- 所有UI组件适配新渲染流程

* 🚨 auto fix by pre-commit hooks

---------

Co-authored-by: webjoin111 <455457521@qq.com>
Co-authored-by: pre-commit-ci[bot] <66853113+pre-commit-ci[bot]@users.noreply.github.com>

zhenxun/ui/models/core/markdown.py

@@ -1,8 +1,14 @@
 from abc import ABC, abstractmethod
+from pathlib import Path
 from typing import Literal
 
+import aiofiles
 from pydantic import BaseModel, Field
 
+from zhenxun.services.log import logger
+
+from .base import RenderableComponent
+
 __all__ = [
     "CodeElement",
     "HeadingElement",
@@ -115,10 +121,35 @@ class ListElement(ContainerElement):
         return "\n".join(lines)
 
 
-class MarkdownData(BaseModel):
+class MarkdownData(RenderableComponent):
     """Markdown转图片的数据模型"""
 
     style_name: str | None = None
     markdown: str
     width: int = 800
     css_path: str | None = None
+
+    @property
+    def template_name(self) -> str:
+        return "components/core/markdown"
+
+    async def get_extra_css(self, theme_manager) -> str:
+        if self.css_path:
+            css_file = Path(self.css_path)
+            if css_file.is_file():
+                async with aiofiles.open(css_file, encoding="utf-8") as f:
+                    return await f.read()
+            else:
+                logger.warning(f"Markdown自定义CSS文件不存在: {self.css_path}")
+        else:
+            style_name = self.style_name or "github-light"
+            css_path = (
+                theme_manager.current_theme.default_assets_dir
+                / "css"
+                / "markdown"
+                / f"{style_name}.css"
+            )
+            if css_path.exists():
+                async with aiofiles.open(css_path, encoding="utf-8") as f:
+                    return await f.read()
+        return ""