Initial commit: audio2text 双语字幕生成服务

- 音频/视频转双语(英/中)SRT 字幕，Docker 容器化，CPU 开发/GPU 生产同一份代码
- faster-whisper ASR(词级时间戳) + 断句时间戳重算 + NLLB 翻译(模型不共驻)
- 分片上传(断点续传) + SQLite 持久化 + 主页/历史/日志页面
- 历史页文件名搜索；缓存定时清理(默认保留7天，可配置)
- 双 Dockerfile(cpu/gpu) + setup/start/stop 脚本

app/controllers/task_router.py

@@ -0,0 +1,88 @@
+"""任务路由：列表 / 状态 / 下载字幕。"""
+
+from __future__ import annotations
+
+from pathlib import Path
+
+from fastapi import APIRouter, Depends, HTTPException, Query
+from fastapi.responses import FileResponse
+from sqlalchemy.orm import Session
+
+from ..config import get_settings
+from ..database import get_db
+from ..models.task import Task
+from ..schemas.task import TaskListResponse, TaskResponse
+
+router = APIRouter(prefix="/api/tasks", tags=["task"])
+
+
+def _to_resp(task: Task) -> TaskResponse:
+    return TaskResponse(
+        id=task.id,
+        filename=task.filename,
+        status=task.status,
+        progress=task.progress,
+        error=task.error,
+        created_at=task.created_at,
+        updated_at=task.updated_at,
+    )
+
+
+@router.get("", response_model=TaskListResponse, summary="任务列表")
+def list_tasks(
+    limit: int = Query(100, ge=1, le=500),
+    offset: int = Query(0, ge=0),
+    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())
+    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)
+
+
+@router.get("/{task_id}", response_model=TaskResponse, summary="任务状态")
+def get_task(task_id: int, db: Session = Depends(get_db)) -> TaskResponse:
+    task = db.get(Task, task_id)
+    if task is None:
+        raise HTTPException(404, f"任务不存在：{task_id}")
+    return _to_resp(task)
+
+
+@router.get("/{task_id}/subtitle", summary="下载字幕")
+def download_subtitle(
+    task_id: int,
+    type: str = Query("bilingual", pattern="^(bilingual|en|zh)$"),
+    db: Session = Depends(get_db),
+) -> FileResponse:
+    task = db.get(Task, task_id)
+    if task is None:
+        raise HTTPException(404, f"任务不存在：{task_id}")
+    if task.status != "done":
+        raise HTTPException(409, f"任务尚未完成（当前状态：{task.status}）")
+
+    rel = {
+        "bilingual": task.bilingual_srt_path,
+        "en": task.en_srt_path,
+        "zh": task.zh_srt_path,
+    }[type]
+    if not rel:
+        raise HTTPException(404, f"该类型字幕不存在：{type}")
+
+    s = get_settings()
+    path = s.output_dir() / rel
+    if not path.is_file():
+        raise HTTPException(404, f"字幕文件丢失：{path}")
+
+    base = Path(task.filename).stem
+    suffix = "" if type == "bilingual" else f".{type}"
+    download_name = f"{base}{suffix}.srt"
+    return FileResponse(
+        path=path,
+        media_type="application/x-subrip",
+        filename=download_name,
+    )