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/controllers/task_router.py

@@ -2,6 +2,7 @@
 
 from __future__ import annotations
 
+from datetime import datetime, timezone
 from pathlib import Path
 
 from fastapi import APIRouter, Depends, HTTPException, Query
@@ -10,7 +11,8 @@ from sqlalchemy.orm import Session
 
 from ..config import get_settings
 from ..database import get_db
-from ..models.task import Task
+from ..models.task import Task, STATUS_UPLOADING
+from ..models.upload_session import UploadSession
 from ..schemas.task import TaskListResponse, TaskResponse
 
 router = APIRouter(prefix="/api/tasks", tags=["task"])
@@ -28,6 +30,31 @@ def _to_resp(task: Task) -> TaskResponse:
     )
 
 
+def _upload_to_resp(session: UploadSession) -> TaskResponse:
+    """把上传中的 UploadSession 映射为虚拟 TaskResponse。
+
+    is_upload=true 让前端走上传状态轮询而非任务轮询。
+    progress = 已传分片数 / 总分片数 × 100（映射到 0-5 区间，与 extract 阶段衔接）。
+    """
+    uploaded = len(session.uploaded_chunks or [])
+    total = session.total_chunks or 1
+    # 上传进度映射到 0-4%（extract 从 5% 开始，留 1% 给 complete 拼接）
+    progress = min(4.0, uploaded / total * 4.0)
+    now = datetime.now(timezone.utc)
+    return TaskResponse(
+        id=0,  # 虚拟 id，前端用 upload_id 轮询
+        filename=session.filename,
+        status=STATUS_UPLOADING,
+        progress=progress,
+        error=None,
+        created_at=session.created_at,
+        updated_at=session.updated_at or now,
+        size_bytes=session.size_bytes,
+        is_upload=True,
+        upload_id=session.upload_id,
+    )
+
+
 @router.get("", response_model=TaskListResponse, summary="任务列表")
 def list_tasks(
     limit: int = Query(100, ge=1, le=500),
@@ -35,14 +62,30 @@ def list_tasks(
     q: str = Query("", description="按文件名模糊搜索（大小写不敏感，匹配子串）"),
     db: Session = Depends(get_db),
 ) -> TaskListResponse:
-    q_base = db.query(Task).order_by(Task.id.desc())
+    # 上传中的会话（pending 状态）也作为虚拟任务返回，让前端能看到上传进度
+    upload_q = db.query(UploadSession).filter(UploadSession.status == "pending")
     if q.strip():
-        # SQLite 的 LIKE 默认大小写不敏感（ASCII），ilike 等价于 LIKE
         like = f"%{q.strip()}%"
-        q_base = q_base.filter(Task.filename.ilike(like))
-    total = q_base.count()
-    tasks = q_base.offset(offset).limit(limit).all()
-    return TaskListResponse(tasks=[_to_resp(t) for t in tasks], total=total)
+        upload_q = upload_q.filter(UploadSession.filename.ilike(like))
+    uploads = upload_q.order_by(UploadSession.created_at.desc()).all()
+
+    # 已创建的 Task（含 extracting/transcribing/.../done/failed）
+    task_q = db.query(Task).order_by(Task.created_at.desc(), Task.id.desc())
+    if q.strip():
+        like = f"%{q.strip()}%"
+        task_q = task_q.filter(Task.filename.ilike(like))
+    total_tasks = task_q.count()
+    tasks = task_q.offset(offset).limit(limit).all()
+
+    # 合并：上传会话 + Task，按 created_at 倒序
+    upload_resps = [_upload_to_resp(s) for s in uploads]
+    task_resps = [_to_resp(t) for t in tasks]
+    all_resps = upload_resps + task_resps
+    all_resps.sort(key=lambda r: r.created_at, reverse=True)
+
+    # 分页：offset/limit 作用于合并后列表（上传会话通常很少，主要影响首页前几条）
+    paged = all_resps[offset:offset + limit]
+    return TaskListResponse(tasks=paged, total=len(all_resps))
 
 
 @router.get("/{task_id}", response_model=TaskResponse, summary="任务状态")