优化抖动幅度和日志双时间显示

- jitterDuration 抖动从 base/3 降至 base/10，避免过大的随机延迟
- 日志新增斗鱼双时间显示：本地时间后追加 (D斗鱼时间)，前端蓝色高亮
- 时间校准后自动同步斗鱼偏移量到日志模块

frontend/src/components/log/LogPanel.vue

@@ -157,6 +157,7 @@ const handleVerify = async () => {
         <template v-if="log.source === 'server'">
           <span class="log-prefix">[后端]</span>
           <span v-if="log.time" class="log-time">[{{ log.time }}]</span>
+          <span v-if="log.douyuTime" class="log-douyu-time">D:{{ log.douyuTime }}</span>
           <span v-if="log.category" class="log-cat">{{ log.category }}</span>
           <span v-if="log.account" class="log-account">{{ log.account }}</span>
           <span class="log-msg">{{ log.message }}</span>
@@ -363,6 +364,13 @@ const handleVerify = async () => {
   font-size: 10px;
 }
 
+.log-douyu-time {
+  color: var(--accent);
+  flex-shrink: 0;
+  font-size: 10px;
+  font-weight: 600;
+}
+
 .log-cat {
   display: inline-block;
   padding: 0 4px;