feat: VRSub 单体应用（WOV 单机版）初始提交

为视频生成 VR 双眼字幕的单体实现：FastAPI 后端、调度器与全部节点
（提音/转写/翻译/ASS/抽帧/OCR/LLM 过滤）在单进程内运行。

- 节点协议（wov_sdk 数据模型）与分布式版保持一致，预留回退桥梁
- 工作流即数据：DAG 存于 workflows/*.json，模型/链路改动只改数据
- 调度器：拓扑顺序执行、断点续跑（产物重建）、任务暂停/继续
- 抽帧按帧间隔（select 按帧号精确取帧），VLM OCR 与 LLM 过滤使用
  自适应线程池弹性并发，并打印数据处理速度进度日志
- 100% 行覆盖率（pytest --cov-fail-under=100）

tests/test_seed.py

@@ -0,0 +1,108 @@
+"""种子数据测试。
+
+验证从 workflows/*.json 数据文件加载默认工作流、幂等性，以及
+开启种子与调度器后的应用生命周期。工作流定义来自数据文件而非代码。
+"""
+
+from pathlib import Path
+
+from fastapi.testclient import TestClient
+
+from wov_app.db import Database
+from wov_app.main import app
+from wov_app.seed import seed_default_workflows
+
+# 单体根目录：tests/ 的上一级。
+WORKSPACE = Path(__file__).resolve().parent.parent
+
+
+def test_seed_default_workflows_idempotent(tmp_path) -> None:
+    """验证从数据文件加载 demo/zh-direct 两个工作流且重复调用幂等。"""
+    db = Database(tmp_path / "wov.db")
+    created = seed_default_workflows(db)
+    assert created == 3
+    assert db.get_workflow("demo") is not None
+    assert db.get_workflow("zh-direct") is not None
+
+    # demo：asr 显式声明 model_path 与长音频参数，模型选择完全数据化。
+    demo = db.get_latest_workflow_version("demo")["definition"]
+    assert demo["name"] == "视频字幕生成"
+    demo_asr = next(node for node in demo["nodes"] if node["id"] == "asr")
+    assert demo_asr["params"]["model_path"] == "faster-whisper-large-v3"
+    assert demo_asr["params"]["condition_on_previous_text"] is False
+
+    # zh-direct：使用中文直出模型并开启翻译任务。
+    zh = db.get_latest_workflow_version("zh-direct")["definition"]
+    assert zh["name"] == "中文直出字幕"
+    zh_asr = next(node for node in zh["nodes"] if node["id"] == "asr")
+    assert zh_asr["params"]["model_path"] == "whisper-large-v2-translate-zh-v0.2-st-ct2"
+    assert zh_asr["params"]["task"] == "translate"
+
+    # 再次调用不重复创建。
+    assert seed_default_workflows(db) == 0
+    assert len(db.list_workflow_versions("demo")) == 1
+
+
+def test_seed_custom_dir_and_empty(tmp_path) -> None:
+    """验证自定义数据目录的加载与空目录返回 0。"""
+    db = Database(tmp_path / "wov.db")
+    custom = tmp_path / "workflows"
+    custom.mkdir()
+    (custom / "a.json").write_text(
+        """
+        {
+          "id": "flow-a",
+          "name": "Flow A",
+          "description": "custom",
+          "version": 1,
+          "definition": {
+            "name": "Flow A",
+            "version": 1,
+            "nodes": [{"id": "step", "node_type": "echo"}],
+            "edges": [],
+            "entry_inputs": {},
+            "final_outputs": {}
+          }
+        }
+        """,
+        encoding="utf-8",
+    )
+    assert seed_default_workflows(db, custom) == 1
+    assert db.get_workflow("flow-a") is not None
+    # 空目录返回 0。
+    empty = tmp_path / "empty"
+    empty.mkdir()
+    assert seed_default_workflows(db, empty) == 0
+    # 已存在的工作流被跳过。
+    assert seed_default_workflows(db, custom) == 0
+
+
+def test_lifespan_with_seed_and_scheduler(monkeypatch) -> None:
+    """验证启用自动种子与调度器后应用正常启动，demo 与中文直出应用均可见。"""
+    monkeypatch.setenv("WOV_AUTO_SEED", "1")
+    monkeypatch.setenv("WOV_SCHEDULER_ENABLED", "1")
+    with TestClient(app) as client:
+        apps = client.get("/api/apps")
+        assert apps.status_code == 200
+        assert any(item["id"] == "demo" for item in apps.json())
+        assert any(item["id"] == "zh-direct" for item in apps.json())
+
+
+def test_seed_workflows_have_chunk_seconds(tmp_path) -> None:
+    """验证内置工作流的 asr 节点均显式声明分块参数。"""
+    db = Database(tmp_path / "wov.db")
+    seed_default_workflows(db)
+    for workflow_id in ("demo", "zh-direct"):
+        definition = db.get_latest_workflow_version(workflow_id)["definition"]
+        asr = next(node for node in definition["nodes"] if node["id"] == "asr")
+        assert asr["params"]["chunk_seconds"] == 60
+
+
+def test_seed_workflows_vad_filter_off(tmp_path) -> None:
+    """验证内置工作流 asr 显式开启 VAD。"""
+    db = Database(tmp_path / "wov.db")
+    seed_default_workflows(db)
+    for workflow_id in ("demo", "zh-direct"):
+        definition = db.get_latest_workflow_version(workflow_id)["definition"]
+        asr = next(node for node in definition["nodes"] if node["id"] == "asr")
+        assert asr["params"]["vad_filter"] is True