style: refine silent subagent toggle layout

Author: Ayleovelle

dashboard/src/views/SubAgentPage.vue

@@ -176,20 +176,21 @@
                     </div>
                   </div>
 
-                  <div class="setting-card setting-card--compact">
-                    <div class="setting-card-head">
-                      <div>
-                        <div class="setting-title">{{ tm('form.silentHandoffLabel') }}</div>
-                        <div class="setting-subtitle">{{ tm('form.silentHandoffHint') }}</div>
-                      </div>
-                      <v-switch
-                        :model-value="agent.default_handoff_mode === 'silent'"
-                        color="primary"
-                        hide-details
-                        inset
-                        density="comfortable"
-                        @update:model-value="agent.default_handoff_mode = $event ? 'silent' : 'normal'"
-                      />
+                  <div class="setting-card setting-card--compact silent-handoff-card">
+                    <div class="silent-handoff-title">
+                      {{ tm('form.silentHandoffLabel') }}
+                    </div>
+                    <v-switch
+                      class="silent-handoff-switch"
+                      :model-value="agent.default_handoff_mode === 'silent'"
+                      color="primary"
+                      hide-details
+                      inset
+                      density="comfortable"
+                      @update:model-value="agent.default_handoff_mode = $event ? 'silent' : 'normal'"
+                    />
+                    <div class="setting-subtitle silent-handoff-hint">
+                      {{ tm('form.silentHandoffHint') }}
                     </div>
                   </div>
 
@@ -503,7 +504,33 @@ onBeforeRouteLeave(async () => {
 }
 
 .setting-card--compact {
-  padding: 14px;
+  padding: 16px;
+}
+
+.silent-handoff-card {
+  display: grid;
+  grid-template-columns: minmax(0, 1fr) auto;
+  align-items: center;
+  gap: 8px 16px;
+}
+
+.silent-handoff-title {
+  min-width: 0;
+  color: var(--dashboard-text);
+  font-size: 15px;
+  font-weight: 700;
+  line-height: 1.45;
+}
+
+.silent-handoff-switch {
+  justify-self: end;
+  align-self: center;
+}
+
+.silent-handoff-hint {
+  grid-column: 1 / -1;
+  max-width: 680px;
+  margin-top: 0;
 }
 
 .setting-card-head {