style: reorganize key list layout — actions to bottom, fix footer wrap

Layout restructure:
- Move Import Keys button from toolbar to footer (left side)
- Move batch action bar (select-all + export/delete) to bottom,
  above the footer, below the tree view
- Toolbar now only contains filter input + refresh/toggle buttons

Footer fix:
- Add min-width:0 + overflow:hidden on left side to truncate long counts
- Add flex-shrink:0 + white-space:nowrap on right side to keep buttons
  from wrapping when key count is large

src/renderer/src/components/key/KeyList.vue

@@ -561,20 +561,6 @@ onUnmounted(() => {
           <el-icon class="search-icon"><Filter /></el-icon>
         </template>
       </el-input>
-      <el-button size="small" @click="importKeys" :disabled="!connStore.activeId" class="import-btn">
-        {{ t('key.importKeys') }}
-      </el-button>
-      <div v-if="multiSelect" class="select-all-wrapper">
-        <label class="select-all-label" @click.prevent="selectAll">
-          <input
-            type="checkbox"
-            class="select-all-checkbox"
-            :checked="multiSelect && selectedKeys.size === filteredKeys.length && filteredKeys.length > 0"
-            :indeterminate="multiSelect && selectedKeys.size > 0 && selectedKeys.size < filteredKeys.length"
-          />
-          <span>{{ t('key.selectAll') }}</span>
-        </label>
-      </div>
       <el-button-group class="key-actions">
         <el-button size="small" @click="refreshKeys" :disabled="!connStore.activeId">
           <el-icon><Refresh /></el-icon>
@@ -589,18 +575,6 @@ onUnmounted(() => {
       </el-button-group>
     </div>
 
-    <div v-if="multiSelect && selectedKeys.size > 0" class="batch-bar">
-      <span class="batch-count">{{ t('key.selected', { n: selectedKeys.size }) }}</span>
-      <div class="batch-bar-actions">
-        <el-button size="small" @click="exportKeys">
-          {{ t('key.exportKeys') }}
-        </el-button>
-        <el-button size="small" type="danger" @click="batchDelete">
-          {{ t('key.batchDelete') }}
-        </el-button>
-      </div>
-    </div>
-
     <div class="key-content">
       <!-- Tree View -->
       <div class="key-tree">
@@ -642,6 +616,30 @@ onUnmounted(() => {
       </div>
     </div>
 
+    <!-- Batch actions bar (bottom) -->
+    <div v-if="multiSelect && selectedKeys.size > 0" class="batch-bar">
+      <div class="batch-bar-left">
+        <label class="select-all-label" @click.prevent="selectAll">
+          <input
+            type="checkbox"
+            class="select-all-checkbox"
+            :checked="multiSelect && selectedKeys.size === filteredKeys.length && filteredKeys.length > 0"
+            :indeterminate="multiSelect && selectedKeys.size > 0 && selectedKeys.size < filteredKeys.length"
+          />
+          <span>{{ t('key.selectAll') }}</span>
+        </label>
+        <span class="batch-count">{{ t('key.selected', { n: selectedKeys.size }) }}</span>
+      </div>
+      <div class="batch-bar-actions">
+        <el-button size="small" @click="exportKeys">
+          {{ t('key.exportKeys') }}
+        </el-button>
+        <el-button size="small" type="danger" @click="batchDelete">
+          {{ t('key.batchDelete') }}
+        </el-button>
+      </div>
+    </div>
+
     <!-- Right-click context menu -->
     <div
       v-if="contextMenu.visible"
@@ -674,7 +672,12 @@ onUnmounted(() => {
     </div>
 
     <div class="key-footer">
+      <div class="key-footer-left">
+        <el-button size="small" @click="importKeys" :disabled="!connStore.activeId">
+          {{ t('key.importKeys') }}
+        </el-button>
         <span class="key-count">{{ t('key.count', { n: keyStore.keys.length }) }}</span>
+      </div>
       <div class="key-footer-actions">
         <el-button
           v-if="keyStore.hasMore && keyStore.loading"
@@ -738,15 +741,21 @@ onUnmounted(() => {
 }
 
 .batch-bar {
-  padding: 8px 12px;
+  padding: 6px 12px;
   display: flex;
   justify-content: space-between;
   align-items: center;
   background: var(--accent-bg);
-  border-bottom: 1px solid var(--border-color);
+  border-top: 1px solid var(--border-color);
   flex-shrink: 0;
 }
 
+.batch-bar-left {
+  display: flex;
+  align-items: center;
+  gap: 12px;
+}
+
 .batch-bar-actions {
   display: flex;
   gap: 6px;
@@ -759,10 +768,6 @@ onUnmounted(() => {
   color: var(--accent-light);
 }
 
-.import-btn {
-  flex-shrink: 0;
-}
-
 .key-content {
   flex: 1;
   overflow: auto;
@@ -859,23 +864,37 @@ onUnmounted(() => {
 }
 
 .key-footer {
-  padding: 8px 12px;
+  padding: 6px 12px;
   border-top: 1px solid var(--border-color);
   display: flex;
   justify-content: space-between;
   align-items: center;
   flex-shrink: 0;
+  gap: 8px;
+}
+
+.key-footer-left {
+  display: flex;
+  align-items: center;
+  gap: 8px;
+  min-width: 0;
+  overflow: hidden;
 }
 
 .key-count {
   font-size: 11px;
   color: var(--text-muted);
+  white-space: nowrap;
+  overflow: hidden;
+  text-overflow: ellipsis;
 }
 
 .key-footer-actions {
   display: flex;
   gap: 6px;
   align-items: center;
+  flex-shrink: 0;
+  white-space: nowrap;
 }
 
 /* Right-click context menu */
@@ -929,13 +948,7 @@ onUnmounted(() => {
   color: var(--danger);
 }
 
-/* Select All checkbox */
-.select-all-wrapper {
-  display: flex;
-  align-items: center;
-  flex-shrink: 0;
-}
-
+/* Select All checkbox (in batch bar) */
 .select-all-label {
   display: flex;
   align-items: center;