feat: 0.8.0 文件夹对比深度增强与字符级逐组预算制 - 按扩展名多选过滤（第四维过滤与其他条件取交集、N/总数计数切换）、目录行双击聚合对比（差异导航限定子树内批量审查、双击文件回全局、空差异提示与折叠态自愈）、增量重扫（size+mtime指纹一致零IO沿用、语义开关翻转按semSame纯内存组合零IO、unreadable不缓存与截断弃缓存、重新扫描按钮）、字符级变更组逐组预算制（超限组仅行级配对输出不再牵连其余组、charModePartial部分降级标记与报告说明、全部组降级仍整体降级）、拖拽导入E2E（dropFiles合成DataTransfer覆盖decodeBuffer IPC全链路4用例）、文档与版本号同步

e2e/app.spec.ts

@@ -8,7 +8,8 @@ import {
   makeTmpDir,
   removeTmpDir,
   writeTextFixture,
-  pasteText
+  pasteText,
+  dropFiles
 } from './helpers'
 
 /**
@@ -292,6 +293,42 @@ test.describe('文件夹对比（主进程真实扫描链路）', () => {
     }
   })
 
+  test('增量重扫：修改文件后点重新扫描，状态正确更新', async () => {
+    const root = await makeTmpDir('difflens-e2e-rescan-')
+    try {
+      const leftDir = join(root, 'left')
+      const rightDir = join(root, 'right')
+      const { mkdir, writeFile: wf } = await import('fs/promises')
+      await mkdir(leftDir, { recursive: true })
+      await mkdir(rightDir, { recursive: true })
+      await wf(join(leftDir, 'same.txt'), 'identical')
+      await wf(join(rightDir, 'same.txt'), 'identical')
+      await wf(join(leftDir, 'diff.txt'), 'left v1')
+      await wf(join(rightDir, 'diff.txt'), 'right v1')
+
+      const { app, window } = await launchApp()
+      await stubOpenDialogSeq(app, [[leftDir], [rightDir]])
+      await window.getByRole('button', { name: '对比文件夹' }).click()
+      await expect(window.getByText('相同 1')).toBeVisible()
+      await expect(window.getByText('不同 1')).toBeVisible()
+
+      // 修改右侧 same.txt（真实 mtime 变化）→ 重新扫描（增量）→ 判定更新
+      await wf(join(rightDir, 'same.txt'), 'identical changed')
+      await window.getByRole('button', { name: '重新扫描' }).click()
+      await expect(window.getByText('相同 0')).toBeVisible()
+      await expect(window.getByText('不同 2')).toBeVisible()
+
+      // 改回一致 → 再扫 → 恢复
+      await wf(join(rightDir, 'same.txt'), 'identical')
+      await window.getByRole('button', { name: '重新扫描' }).click()
+      await expect(window.getByText('相同 1')).toBeVisible()
+      await expect(window.getByText('不同 1')).toBeVisible()
+      await app.close()
+    } finally {
+      await removeTmpDir(root)
+    }
+  })
+
   test('语义判等、树形折叠、搜索与文件夹报告导出', async () => {
     const root = await makeTmpDir('difflens-e2e-folder2-')
     try {
@@ -353,6 +390,58 @@ test.describe('文件夹对比（主进程真实扫描链路）', () => {
   })
 })
 
+test.describe('拖拽导入（真实 Chromium DataTransfer 链路）', () => {
+  test('空面板拖入文件：内容渲染与文件名显示', async () => {
+    const { app, window } = await launchApp()
+    await dropFiles(window, '.pane-empty', [
+      { name: 'dropped-left.txt', content: 'drag line 1\ndrag line 2' }
+    ])
+    // 文件名出现在面板头，内容渲染（file.arrayBuffer → decodeBuffer IPC → 编码探测全链路）
+    await expect(window.locator('.pane-file').filter({ hasText: 'dropped-left.txt' })).toBeVisible()
+    await expect(window.getByText('drag line 1').first()).toBeVisible()
+    await app.close()
+  })
+
+  test('双侧拖入形成对比：差异渲染', async () => {
+    const { app, window } = await launchApp()
+    await dropFiles(window, '.pane-empty', [
+      { name: 'a.txt', content: 'same\nleft-unique' }
+    ])
+    // 左侧装载后进入对比视图：右侧为 DiffView 面板（.pane-right），不再是空态
+    await dropFiles(window, '.pane-right', [
+      { name: 'b.txt', content: 'same\nright-unique' }
+    ])
+    await expect(window.getByText('有差异')).toBeVisible()
+    await expect(window.getByText('left-unique').first()).toBeVisible()
+    await expect(window.getByText('right-unique').first()).toBeVisible()
+    await app.close()
+  })
+
+  test('拖入非文本扩展名被拒绝并提示', async () => {
+    const { app, window } = await launchApp()
+    await dropFiles(window, '.pane-empty', [
+      { name: 'image.png', content: 'fake-binary', type: 'image/png' }
+    ])
+    await expect(window.getByText(/仅支持文本文件：image\.png/)).toBeVisible()
+    // 保持空态（无导出入口）
+    await expect(window.getByRole('button', { name: '导出报告' })).toHaveCount(0)
+    await app.close()
+  })
+
+  test('多文件拖入提示已取第一个并加载首个文件', async () => {
+    const { app, window } = await launchApp()
+    await dropFiles(window, '.pane-empty', [
+      { name: 'first.txt', content: 'first content' },
+      { name: 'second.txt', content: 'second content' }
+    ])
+    await expect(window.getByText(/一次只能导入一个文件/)).toBeVisible()
+    await expect(
+      window.locator('.pane-file').filter({ hasText: 'first.txt' })
+    ).toBeVisible()
+    await app.close()
+  })
+})
+
 test.describe('偏好持久化（跨实例重启）', () => {
   test('重启后恢复比较选项与视图开关', async () => {
     // 第一实例 fresh 清掉历史残留，建立干净基线后再写入偏好

e2e/helpers.ts

@@ -93,3 +93,30 @@ export async function pasteText(window: Page, side: 'left' | 'right', text: stri
   await window.getByPlaceholder(/粘贴或输入/).fill(text)
   await window.getByRole('button', { name: '开始对比' }).click()
 }
+
+/**
+ * 向指定选择器元素派发合成拖放（真实 Chromium 支持 DataTransfer/DragEvent 构造）。
+ * 覆盖渲染进程拖拽导入全链路：dropPane 走 file.arrayBuffer → decodeBuffer IPC → 编码探测。
+ * 先派发 dragover（preventDefault 激活 drop 目标）再派发 drop。
+ */
+export async function dropFiles(
+  window: Page,
+  selector: string,
+  files: { name: string; content: string; type?: string }[]
+): Promise<void> {
+  await window.evaluate(
+    ({ sel, specs }) => {
+      const el = document.querySelector(sel)
+      if (!el) throw new Error(`dropFiles: selector not found: ${sel}`)
+      const dt = new DataTransfer()
+      for (const f of specs) {
+        dt.items.add(new File([f.content], f.name, { type: f.type ?? 'text/plain' }))
+      }
+      el.dispatchEvent(
+        new DragEvent('dragover', { bubbles: true, cancelable: true, dataTransfer: dt })
+      )
+      el.dispatchEvent(new DragEvent('drop', { bubbles: true, cancelable: true, dataTransfer: dt }))
+    },
+    { sel: selector, specs: files }
+  )
+}