feat: add video-split config knobs and reproducible script

tests/unit/test_pool_config_video_split.py

@@ -0,0 +1,115 @@
+"""视频级切分科研旋钮单元测试：诊断指纹 + val_wrong_min 功效护栏 + PoolConfig 新字段。
+
+覆盖：
+    - diag_fingerprint 对 (prompt 版本 / 模型 / 代码版本) 三元组确定且敏感；
+    - split_by_video_assignment 的 val_wrong_min 门控 fail loud（验证信号不足即报错）；
+    - val_wrong_min 默认 0 时行为与 Task 11 现有调用完全一致（不回归）；
+    - PoolConfig 能接收视频级切分的五个新旋钮字段（纯 dataclass 装配）。
+"""
+
+from __future__ import annotations
+
+import pytest
+
+from app.harness.pools import InsufficientValSignal, split_by_video_assignment
+from app.harness.split_selection import diag_fingerprint
+from core.types import GeneratedQuestion, PoolConfig
+
+
+def _q(qid: str, vid: str, tt: str = "Counting Problem") -> GeneratedQuestion:
+    """构造最小可用题目（补齐 GeneratedQuestion 的必填 source_nodes/difficulty）。"""
+    return GeneratedQuestion(
+        question_id=qid,
+        video_id=vid,
+        task_type=tt,
+        question="",
+        options=("A", "B", "C", "D"),
+        answer="A",
+        source_nodes=(),
+        difficulty="easy",
+    )
+
+
+def test_diag_fingerprint_deterministic_and_sensitive():
+    """诊断指纹对相同三元组稳定，对任一分量变化敏感。"""
+    a = diag_fingerprint("p1", "deepseek-v4", "abc123")
+    assert a == diag_fingerprint("p1", "deepseek-v4", "abc123")  # 确定性
+    assert a != diag_fingerprint("p2", "deepseek-v4", "abc123")  # prompt 变则变
+    assert a != diag_fingerprint("p1", "kimi", "abc123")  # model 变则变
+    assert a != diag_fingerprint("p1", "deepseek-v4", "def456")  # 代码版本变则变
+    assert len(a) == 16  # sha256 截断 16 位十六进制
+
+
+def test_val_wrong_min_enforced():
+    """val 错题数 < val_wrong_min 时 fail loud（InsufficientValSignal），不静默兜底。"""
+    qs = [_q("v1-1", "v1"), _q("v1-2", "v1"), _q("v1-3", "v1")]
+    correctness = {q.question_id: True for q in qs}  # 全对 → val 无错题
+    with pytest.raises(InsufficientValSignal):  # val 错题 < val_wrong_min
+        split_by_video_assignment(
+            qs,
+            {"v1": "trainval"},
+            correctness=correctness,
+            val_ratio=0.5,
+            seed=0,
+            val_wrong_min=5,
+        )
+
+
+def test_val_wrong_min_default_zero_no_regression():
+    """val_wrong_min 默认 0 时不检查错题数，保持 Task 11 现有调用契约不破。"""
+    qs = [_q("v1-1", "v1"), _q("v2-1", "v2")]
+    assignment = {"v1": "trainval", "v2": "trainval"}
+    correctness = {"v1-1": True, "v2-1": True}  # 全对但默认不触发护栏
+    pools = split_by_video_assignment(
+        qs, assignment, correctness=correctness, val_ratio=1.0, seed=0
+    )
+    assert len(pools.validation) == 2  # 未抛异常，正常返回
+
+
+def test_pool_config_accepts_video_split_knobs():
+    """PoolConfig 能接收视频级切分五个新旋钮字段（默认惰性，不破坏现有构造点）。"""
+    cfg = PoolConfig(
+        task_types=None,
+        seed=0,
+        baseline_run_id="infer_adhoc",
+        diag_size=200,
+        diag_correct_ratio=0.5,
+        val_size=30,
+        val_correct_ratio=0.5,
+        test_size=60,
+        eval_min_per_class=2,
+        train_ratio=0.667,
+        test_questions_dir=None,
+        n_trainval=100,
+        floor_k={"Counting Problem": 3},
+        epsilon=0.1,
+        report_floor=27,
+        val_wrong_min=20,
+    )
+    assert cfg.n_trainval == 100
+    assert cfg.floor_k == {"Counting Problem": 3}
+    assert cfg.epsilon == 0.1
+    assert cfg.report_floor == 27
+    assert cfg.val_wrong_min == 20
+
+
+def test_pool_config_video_split_knobs_default_inert():
+    """未传视频级切分字段时默认惰性（0 / 空 dict），不破坏 GlobalPoolStrategy 现有构造。"""
+    cfg = PoolConfig(
+        task_types=None,
+        seed=0,
+        baseline_run_id="run_1",
+        diag_size=200,
+        diag_correct_ratio=0.5,
+        val_size=30,
+        val_correct_ratio=0.5,
+        test_size=60,
+        eval_min_per_class=2,
+        train_ratio=0.667,
+        test_questions_dir=None,
+    )
+    assert cfg.n_trainval == 0
+    assert cfg.floor_k == {}
+    assert cfg.epsilon == 0.0
+    assert cfg.report_floor == 0
+    assert cfg.val_wrong_min == 0