refactor(ui): 统一编辑图标为铅笔 SVG

- Account 页面昵称编辑：修改文字 → 铅笔图标
- 移除保存/取消按钮，统一为 Enter 保存、Esc/失焦取消

tauri-app/src/pages/Profile/Account.tsx

@@ -88,44 +88,54 @@ export default function Account() {
           <span className="settings-row-label">昵称</span>
           <span className="settings-row-value" style={{ display: 'flex', alignItems: 'center', gap: 'var(--spacing-sm)' }}>
             {editing ? (
-              <>
-                <input
-                  type="text"
-                  value={nickname}
-                  onChange={(e) => setNickname(e.target.value)}
-                  maxLength={20}
-                  autoFocus
-                  style={{
-                    padding: '4px 10px',
-                    borderRadius: '6px',
-                    border: '1px solid var(--border-color)',
-                    fontSize: 'var(--font-sm)',
-                    outline: 'none',
-                    width: '160px',
-                  }}
-                  onKeyDown={(e) => { if (e.key === 'Enter') handleSaveNickname(); }}
-                />
-                <button
-                  className="btn btn-primary btn-sm"
-                  onClick={handleSaveNickname}
-                  disabled={saving}
-                >
-                  {saving ? '保存中' : '保存'}
-                </button>
-                <button
-                  className="btn btn-ghost btn-sm"
-                  onClick={() => { setEditing(false); setNickname(displayName); setError(''); }}
-                  disabled={saving}
-                >
-                  取消
-                </button>
-              </>
+              <input
+                type="text"
+                value={nickname}
+                onChange={(e) => setNickname(e.target.value)}
+                maxLength={20}
+                autoFocus
+                disabled={saving}
+                style={{
+                  padding: '4px 10px',
+                  borderRadius: '6px',
+                  border: '1px solid var(--border-color)',
+                  fontSize: 'var(--font-sm)',
+                  outline: 'none',
+                  width: '160px',
+                  fontFamily: 'inherit',
+                }}
+                onKeyDown={(e) => {
+                  if (e.key === 'Enter') handleSaveNickname();
+                  if (e.key === 'Escape') {
+                    setEditing(false);
+                    setNickname(displayName);
+                    setError('');
+                  }
+                }}
+                onBlur={() => {
+                  setEditing(false);
+                  setNickname(displayName);
+                  setError('');
+                }}
+              />
             ) : (
               <>
                 <span>{displayName}</span>
-                <button className="btn btn-ghost btn-sm" onClick={() => setEditing(true)}>
-                  修改
-                </button>
+                <svg
+                  width="14"
+                  height="14"
+                  viewBox="0 0 24 24"
+                  fill="none"
+                  stroke="#36b26a"
+                  strokeWidth={2}
+                  strokeLinecap="round"
+                  strokeLinejoin="round"
+                  style={{ cursor: 'pointer', flexShrink: 0 }}
+                  onClick={() => setEditing(true)}
+                >
+                  <title>修改昵称</title>
+                  <path d="M17 3a2.828 2.828 0 1 1 4 4L7.5 20.5 2 22l1.5-5.5L17 3z" />
+                </svg>
               </>
             )}
           </span>