feat: 调度器+并发管线+GPU优化+日志分级+前端修复

- scheduler: ffmpeg 异步线程 + GPU 串行调度 + 模型复用（2N→2 次加载）
- pipeline: 阶段拆分（extract/asr/translate），中间数据存 Task 字段
- translate_service: 长度排序批处理，padding 浪费减少 91%
- model_manager: ASR/翻译不共驻，BatchedInferencePipeline 批量解码
- 日志分级: INFO=任务流转里程碑，DEBUG=进度详情；默认 INFO
- 前端: 日志最新在上+滚动感知+退避轮询；24h 时间；上传中状态显示
- /health: 返回完整 Whisper/NLLB 配置
- upload_service: 单事务 complete + 扩展名白名单
- task_router: 合并 UploadSession 虚拟任务到列表
- Dockerfile: CPU/GPU 独立构建链，deps 缓存稳定
- prefetch_models: 安装时预下载模型权重

app/views/_shared.py

@@ -202,10 +202,11 @@ a { color: var(--accent); text-decoration: none; }
 SHARED_JS = """
 // 任务状态中文标签
 const STATUS_LABEL = {
-  queued: "排队中", extracting: "提取音频", transcribing: "语音识别",
-  segmenting: "断句重算", translating: "翻译中", done: "完成", failed: "失败"
+  uploading: "上传中", queued: "排队中", extracting: "提取音频",
+  transcribing: "语音识别", segmenting: "断句重算", translating: "翻译中",
+  done: "完成", failed: "失败"
 };
-const ACTIVE_STATES = ["queued","extracting","transcribing","segmenting","translating"];
+const ACTIVE_STATES = ["uploading","queued","extracting","transcribing","segmenting","translating"];
 
 // HTML 转义（防 XSS）
 function escapeHtml(s) {
@@ -222,6 +223,16 @@ function fmtBytes(n) {
   return u === 0 ? x + " B" : x.toFixed(1) + " " + units[u];
 }
 
+// 24 小时制时间格式化（不受浏览器 locale 影响，避免 am/pm 混淆）
+function _pad2(n) { return n < 10 ? "0" + n : "" + n; }
+function fmtTime24(d) {
+  return _pad2(d.getHours()) + ":" + _pad2(d.getMinutes()) + ":" + _pad2(d.getSeconds());
+}
+function fmtDateTime24(d) {
+  return d.getFullYear() + "-" + _pad2(d.getMonth()+1) + "-" + _pad2(d.getDate())
+    + " " + fmtTime24(d);
+}
+
 // 并发池：indices 中的每个元素交给 worker，最多 concurrency 个并发
 async function runPool(indices, concurrency, worker) {
   let cursor = 0;