feat(预览): 支持图片文件预览和Markdown相对路径解析

- 新增图片类型标签页，用于预览本地图片文件
- 在useTabs中根据文件扩展名自动识别图片文件并设置tab类型
- 为Preview组件添加文件路径属性，用于解析Markdown中的相对图片路径
- 实现Markdown渲染器对相对路径的解析，将相对路径转换为file://协议URL
- 添加图片点击预览功能，点击Markdown中的图片可放大查看

src/components/FileTab.vue

@@ -7,7 +7,7 @@
       />
     </div>
     <div class="preview-pane" v-show="mode !== 'source'" :style="{ width: mode === 'split' ? '50%' : '100%' }">
-      <Preview :content="localContent" />
+      <Preview :content="localContent" :file-path="tab.filePath" />
     </div>
     
     <!-- 模式切换浮动按钮 -->

src/components/ImageTab.vue

@@ -0,0 +1,48 @@
+<template>
+  <div class="image-tab">
+    <div v-if="fileUrl" class="image-container">
+      <a-image :src="fileUrl" :preview="true" />
+    </div>
+    <div v-else class="empty-state">
+      无法预览该图片
+    </div>
+  </div>
+</template>
+
+<script setup>
+import { computed } from 'vue';
+
+const props = defineProps({
+  tab: {
+    type: Object,
+    required: true
+  }
+});
+
+const toFileUrl = (absolutePath) => {
+  if (!absolutePath) return '';
+  const normalized = absolutePath.replace(/\\/g, '/');
+  return encodeURI(`file:///${normalized}`);
+};
+
+const fileUrl = computed(() => toFileUrl(props.tab.filePath));
+</script>
+
+<style scoped>
+.image-tab {
+  height: 100%;
+  display: flex;
+  overflow: auto;
+  background-color: #fff;
+}
+
+.image-container {
+  margin: auto;
+  padding: 16px;
+}
+
+.empty-state {
+  margin: auto;
+  color: #999;
+}
+</style>

src/components/Preview.vue

@@ -1,24 +1,86 @@
 <template>
-  <div class="markdown-preview" v-html="htmlContent"></div>
+  <div class="markdown-preview" v-html="htmlContent" @click="handleClick"></div>
+  <a-modal v-model:open="imagePreviewOpen" :footer="null" width="80vw" centered>
+    <img v-if="imagePreviewSrc" :src="imagePreviewSrc" style="max-width: 100%; max-height: 75vh; display: block; margin: 0 auto;" />
+  </a-modal>
 </template>
 
 <script setup>
-import { computed } from 'vue';
+import { computed, ref } from 'vue';
 import MarkdownIt from 'markdown-it';
 
 const props = defineProps({
-  content: String
+  content: String,
+  filePath: String
 });
 
+const isAbsoluteOrSpecialUrl = (rawUrl) => {
+  if (!rawUrl) return true;
+  if (rawUrl.startsWith('#')) return true;
+  if (rawUrl.startsWith('//')) return true;
+  return /^[a-zA-Z][a-zA-Z\d+\-.]*:/.test(rawUrl);
+};
+
+const getBaseDirFileUrl = (filePath) => {
+  if (!filePath) return '';
+  const normalized = filePath.replace(/\\/g, '/');
+  const lastSlashIndex = normalized.lastIndexOf('/');
+  const dirPath = lastSlashIndex >= 0 ? normalized.slice(0, lastSlashIndex + 1) : normalized;
+  return encodeURI(`file:///${dirPath}`);
+};
+
+const resolveToFileUrl = (rawUrl, baseDirFileUrl) => {
+  if (!rawUrl || !baseDirFileUrl) return rawUrl || '';
+  if (isAbsoluteOrSpecialUrl(rawUrl)) return rawUrl;
+  try {
+    return new URL(rawUrl, baseDirFileUrl).href;
+  } catch {
+    return rawUrl;
+  }
+};
+
 const md = new MarkdownIt({
   html: true,
   linkify: true,
   typographer: true
 });
 
+const defaultImageRule = md.renderer.rules.image;
+md.renderer.rules.image = (tokens, idx, options, env, self) => {
+  const token = tokens[idx];
+  const src = token.attrGet('src');
+  const resolved = resolveToFileUrl(src, env?.baseDirFileUrl);
+  if (resolved) token.attrSet('src', resolved);
+  if (defaultImageRule) return defaultImageRule(tokens, idx, options, env, self);
+  return self.renderToken(tokens, idx, options);
+};
+
+const defaultLinkOpenRule = md.renderer.rules.link_open;
+md.renderer.rules.link_open = (tokens, idx, options, env, self) => {
+  const token = tokens[idx];
+  const href = token.attrGet('href');
+  const resolved = resolveToFileUrl(href, env?.baseDirFileUrl);
+  if (resolved) token.attrSet('href', resolved);
+  if (defaultLinkOpenRule) return defaultLinkOpenRule(tokens, idx, options, env, self);
+  return self.renderToken(tokens, idx, options);
+};
+
 const htmlContent = computed(() => {
-  return md.render(props.content || '');
+  const env = { baseDirFileUrl: getBaseDirFileUrl(props.filePath) };
+  return md.render(props.content || '', env);
 });
+
+const imagePreviewOpen = ref(false);
+const imagePreviewSrc = ref('');
+
+const handleClick = (event) => {
+  const target = event?.target;
+  if (!target || target.tagName !== 'IMG') return;
+  const src = target.getAttribute('src') || '';
+  if (!src) return;
+  imagePreviewSrc.value = src;
+  imagePreviewOpen.value = true;
+};
 </script>
 
 <style>

src/components/TabContainer.vue

@@ -13,6 +13,11 @@
           v-show="tab.id === state.activeTabId"
           :tab="tab"
         />
+        <ImageTab
+          v-else-if="tab.type === 'image'"
+          v-show="tab.id === state.activeTabId"
+          :tab="tab"
+        />
       </template>
       
       <div v-if="!activeTab" class="empty-state">
@@ -26,6 +31,7 @@
 import TabBar from './TabBar.vue';
 import HomeTab from './HomeTab.vue';
 import FileTab from './FileTab.vue';
+import ImageTab from './ImageTab.vue';
 import { useTabs } from '../composables/useTabs';
 
 const { state, activeTab } = useTabs();

src/composables/useTabs.js

@@ -32,10 +32,13 @@ export function useTabs() {
       return;
     }
 
+    const isImageFile = (name) => /\.(png|jpe?g|gif|webp|bmp|svg|ico)$/i.test(name || '');
+    const tabType = isImageFile(fileNode.name) ? 'image' : 'file';
+
     // 创建新 Tab
     const newTab = {
       id: uuidv4(),
-      type: 'file',
+      type: tabType,
       title: fileNode.name,
       filePath: fileNode.path,
       content: '', // 内容稍后加载，或在组件挂载时加载