完善 TipTap 编辑器与个人资料页：头像裁剪、Tab 缩进、文章内链、Markdown 工具与 Tooltip，并更新样式与 Feed 缓存。

Co-authored-by: Cursor <cursoragent@cursor.com>

frontend/src/components/editor/TabIndentExtension.tsx

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+import { Extension } from '@tiptap/core';
+import type { Editor } from '@tiptap/react';
+
+export const TAB_SPACES = '    ';
+
+/** 收集选区覆盖的文本块 */
+function collectSelectedTextblocks(editor: Editor): { pos: number }[] {
+  const { from, to } = editor.state.selection;
+  const blocks: { pos: number }[] = [];
+  editor.state.doc.nodesBetween(from, to, (node, pos) => {
+    if (node.isTextblock) {
+      blocks.push({ pos });
+      return false;
+    }
+    return undefined;
+  });
+  return blocks;
+}
+
+/** 代码块多行选区：每行首插入缩进 */
+function indentCodeBlockSelection(editor: Editor): boolean {
+  const { from, to, empty } = editor.state.selection;
+  if (empty) return false;
+
+  const text = editor.state.doc.textBetween(from, to, '\n', '\n');
+  const lineStarts = [from];
+  for (let i = 0; i < text.length; i += 1) {
+    if (text[i] === '\n') lineStarts.push(from + i + 1);
+  }
+
+  let tr = editor.state.tr;
+  let offset = 0;
+  lineStarts.forEach(pos => {
+    tr = tr.insertText(TAB_SPACES, pos + offset);
+    offset += TAB_SPACES.length;
+  });
+  editor.view.dispatch(tr);
+  return true;
+}
+
+/** 代码块多行选区：每行首移除最多 4 个空格 */
+function outdentCodeBlockSelection(editor: Editor): boolean {
+  const { from, to, empty } = editor.state.selection;
+  if (empty) return false;
+
+  const doc = editor.state.doc;
+  const text = doc.textBetween(from, to, '\n', '\n');
+  const lineStarts = [from];
+  for (let i = 0; i < text.length; i += 1) {
+    if (text[i] === '\n') lineStarts.push(from + i + 1);
+  }
+
+  let tr = editor.state.tr;
+  let offset = 0;
+  let changed = false;
+  lineStarts.forEach(pos => {
+    const adjPos = pos + offset;
+    const lineEnd = doc.textBetween(adjPos, to + offset).split('\n')[0] ?? '';
+    const match = lineEnd.match(/^ {1,4}/);
+    if (!match) return;
+    tr = tr.delete(adjPos, adjPos + match[0].length);
+    offset -= match[0].length;
+    changed = true;
+  });
+
+  if (!changed) return false;
+  editor.view.dispatch(tr);
+  return true;
+}
+
+/** 多行选区：在每个文本块行首插入缩进 */
+function indentSelection(editor: Editor): boolean {
+  const { empty } = editor.state.selection;
+  if (empty) return false;
+
+  if (editor.isActive('codeBlock')) {
+    return indentCodeBlockSelection(editor);
+  }
+
+  if (editor.isActive('listItem')) {
+    return editor.chain().focus().sinkListItem('listItem').run();
+  }
+
+  const blocks = collectSelectedTextblocks(editor);
+  if (blocks.length === 0) return false;
+
+  let tr = editor.state.tr;
+  let offset = 0;
+  blocks.forEach(({ pos }) => {
+    const insertPos = pos + 1 + offset;
+    tr = tr.insertText(TAB_SPACES, insertPos);
+    offset += TAB_SPACES.length;
+  });
+  editor.view.dispatch(tr);
+  return true;
+}
+
+/** 多行选区：移除每个文本块行首最多 4 个空格 */
+function outdentSelection(editor: Editor): boolean {
+  const { empty } = editor.state.selection;
+  if (empty) return false;
+
+  if (editor.isActive('codeBlock')) {
+    return outdentCodeBlockSelection(editor);
+  }
+
+  if (editor.isActive('listItem')) {
+    return editor.chain().focus().liftListItem('listItem').run();
+  }
+
+  const blocks = collectSelectedTextblocks(editor);
+  if (blocks.length === 0) return false;
+
+  let tr = editor.state.tr;
+  let offset = 0;
+  blocks.forEach(({ pos }) => {
+    const node = editor.state.doc.nodeAt(pos);
+    if (!node?.isTextblock) return;
+    const text = node.textContent;
+    const match = text.match(/^ {1,4}/);
+    if (!match) return;
+    const removeLen = match[0].length;
+    const from = pos + 1 + offset;
+    tr = tr.delete(from, from + removeLen);
+    offset -= removeLen;
+  });
+
+  if (tr.steps.length === 0) return false;
+  editor.view.dispatch(tr);
+  return true;
+}
+
+/** 在代码块或段落中移除光标前的 4 个空格缩进 */
+function outdentTextblock(editor: Editor): boolean {
+  const { state } = editor;
+  const { $from, empty } = state.selection;
+  if (!empty) return false;
+  if (!$from.parent.isTextblock) return false;
+
+  const lineStart = $from.start();
+  const beforeCursor = state.doc.textBetween(lineStart, $from.pos);
+
+  if (beforeCursor.endsWith(TAB_SPACES)) {
+    return editor.chain().focus().deleteRange({ from: $from.pos - TAB_SPACES.length, to: $from.pos }).run();
+  }
+
+  const leading = beforeCursor.match(/^ {1,4}/);
+  if (leading) {
+    return editor.chain().focus().deleteRange({ from: lineStart, to: lineStart + leading[0].length }).run();
+  }
+
+  return false;
+}
+
+/** Tab 缩进：列表缩进/反缩进，多行选区整体缩进，其余插入 4 个空格 */
+export const TabIndent = Extension.create({
+  name: 'tabIndent',
+
+  addKeyboardShortcuts() {
+    return {
+      Tab: ({ editor }) => {
+        if (!editor.state.selection.empty) {
+          return indentSelection(editor);
+        }
+
+        if (editor.isActive('codeBlock')) {
+          return editor.chain().focus().insertContent(TAB_SPACES).run();
+        }
+        if (editor.isActive('listItem')) {
+          return editor.chain().focus().sinkListItem('listItem').run();
+        }
+        return editor.chain().focus().insertContent(TAB_SPACES).run();
+      },
+      'Shift-Tab': ({ editor }) => {
+        if (!editor.state.selection.empty) {
+          return outdentSelection(editor);
+        }
+
+        if (editor.isActive('codeBlock')) {
+          return outdentTextblock(editor);
+        }
+        if (editor.isActive('listItem')) {
+          return editor.chain().focus().liftListItem('listItem').run();
+        }
+        return outdentTextblock(editor);
+      },
+    };
+  },
+});