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/schemas/task.py

@@ -0,0 +1,69 @@
+"""任务与分片上传接口 DTO。"""
+
+from __future__ import annotations
+
+from datetime import datetime
+
+from pydantic import BaseModel, Field
+
+
+# ---------------- 分片上传（对齐 server 的协议） ----------------
+
+class CreateSessionRequest(BaseModel):
+    """创建一个分片上传会话。"""
+
+    filename: str = Field(..., description="客户端原始文件名")
+    size_bytes: int = Field(..., ge=0, description="文件总字节数")
+    chunk_size: int = Field(..., gt=0, description="分片大小（字节）")
+    total_chunks: int = Field(..., gt=0, description="分片总数")
+
+
+class CreateSessionResponse(BaseModel):
+    upload_id: str
+    filename: str
+    size_bytes: int
+    chunk_size: int
+    total_chunks: int
+
+
+class SessionStatusResponse(BaseModel):
+    upload_id: str
+    filename: str
+    size_bytes: int
+    chunk_size: int
+    total_chunks: int
+    uploaded_chunks: list[int]
+    completed: bool
+    task_id: int | None = Field(None, description="completed=true 时指向 Task.id")
+
+
+class ChunkUploadResponse(BaseModel):
+    upload_id: str
+    index: int
+    uploaded_chunks: list[int]
+
+
+class CompleteResponse(BaseModel):
+    """complete 的回执：创建出转写任务，返回 task_id。"""
+
+    task_id: int
+    filename: str
+    size_bytes: int
+    status: str
+
+
+# ---------------- 任务查询 ----------------
+
+class TaskResponse(BaseModel):
+    id: int
+    filename: str
+    status: str
+    progress: float
+    error: str | None
+    created_at: datetime
+    updated_at: datetime
+
+
+class TaskListResponse(BaseModel):
+    tasks: list[TaskResponse]
+    total: int