feat(sidebar): add account data clear action and detail feedback

src/components/Sidebar.scss

@@ -10,8 +10,11 @@
   &.collapsed {
     width: 64px;
 
-    .sidebar-user-card {
+    .sidebar-user-card-wrap {
       margin: 0 8px 8px;
+    }
+
+    .sidebar-user-card {
       padding: 8px 0;
       justify-content: center;
 
@@ -37,8 +40,39 @@
   }
 }
 
-.sidebar-user-card {
+.sidebar-user-card-wrap {
+  position: relative;
   margin: 0 12px 10px;
+}
+
+.sidebar-user-clear-trigger {
+  position: absolute;
+  left: 0;
+  right: 0;
+  bottom: calc(100% + 8px);
+  z-index: 12;
+  border: 1px solid rgba(255, 59, 48, 0.28);
+  border-radius: 10px;
+  background: var(--bg-secondary);
+  color: #d93025;
+  padding: 8px 10px;
+  display: flex;
+  align-items: center;
+  gap: 8px;
+  font-size: 12px;
+  font-weight: 600;
+  cursor: pointer;
+  box-shadow: 0 8px 20px rgba(15, 23, 42, 0.12);
+  transition: background 0.2s ease, color 0.2s ease, border-color 0.2s ease;
+
+  &:hover {
+    background: rgba(255, 59, 48, 0.08);
+    border-color: rgba(255, 59, 48, 0.46);
+  }
+}
+
+.sidebar-user-card {
+  width: 100%;
   padding: 10px;
   border: 1px solid var(--border-color);
   border-radius: 12px;
@@ -47,6 +81,18 @@
   align-items: center;
   gap: 10px;
   min-height: 56px;
+  cursor: pointer;
+  transition: border-color 0.2s ease, background 0.2s ease, box-shadow 0.2s ease;
+
+  &:hover {
+    border-color: rgba(99, 102, 241, 0.32);
+    background: var(--bg-tertiary);
+  }
+
+  &.menu-open {
+    border-color: rgba(99, 102, 241, 0.44);
+    box-shadow: 0 0 0 2px rgba(99, 102, 241, 0.12);
+  }
 
   .user-avatar {
     width: 36px;
@@ -74,6 +120,7 @@
 
   .user-meta {
     min-width: 0;
+    flex: 1;
   }
 
   .user-name {
@@ -93,6 +140,17 @@
     overflow: hidden;
     text-overflow: ellipsis;
   }
+
+  .user-menu-caret {
+    color: var(--text-tertiary);
+    display: inline-flex;
+    transition: transform 0.2s ease, color 0.2s ease;
+
+    &.open {
+      transform: rotate(180deg);
+      color: var(--text-secondary);
+    }
+  }
 }
 
 .nav-menu {
@@ -206,6 +264,82 @@
   }
 }
 
+.sidebar-clear-dialog-overlay {
+  position: fixed;
+  inset: 0;
+  background: rgba(15, 23, 42, 0.3);
+  display: flex;
+  align-items: center;
+  justify-content: center;
+  z-index: 1100;
+  padding: 20px;
+}
+
+.sidebar-clear-dialog {
+  width: min(460px, 100%);
+  background: var(--bg-secondary);
+  border: 1px solid var(--border-color);
+  border-radius: 16px;
+  box-shadow: 0 18px 40px rgba(15, 23, 42, 0.24);
+  padding: 18px 18px 16px;
+
+  h3 {
+    margin: 0;
+    font-size: 16px;
+    color: var(--text-primary);
+  }
+
+  p {
+    margin: 10px 0 0;
+    font-size: 13px;
+    line-height: 1.6;
+    color: var(--text-secondary);
+  }
+}
+
+.sidebar-clear-options {
+  margin-top: 14px;
+  display: flex;
+  gap: 14px;
+  flex-wrap: wrap;
+
+  label {
+    display: inline-flex;
+    align-items: center;
+    gap: 6px;
+    font-size: 13px;
+    color: var(--text-primary);
+  }
+}
+
+.sidebar-clear-actions {
+  margin-top: 18px;
+  display: flex;
+  justify-content: flex-end;
+  gap: 10px;
+
+  button {
+    border: 1px solid var(--border-color);
+    border-radius: 10px;
+    padding: 8px 14px;
+    font-size: 13px;
+    cursor: pointer;
+    background: var(--bg-secondary);
+    color: var(--text-primary);
+  }
+
+  button:disabled {
+    cursor: not-allowed;
+    opacity: 0.6;
+  }
+
+  .danger {
+    border-color: #ef4444;
+    background: #ef4444;
+    color: #fff;
+  }
+}
+
 // 繁花如梦主题：侧边栏毛玻璃 + 激活项用主品牌色
 [data-theme="blossom-dream"] .sidebar {
   background: rgba(255, 255, 255, 0.6);