refactor(question_gen): adapt generator/gates/store signatures for strategy

- generator_v2: _load_prompt_template takes template_name str instead of
  QuestionFamilySpec; _build_v2_prompt takes prompt_template + strategy_name
  + sub_pattern_instruction; generate_one_v2 takes discrete params
  (prompt_template, strategy_name, skill_target, sub_pattern_instruction)
- gates: _gate_leak_test and run_gates take leak_probe_template str
  instead of QuestionFamilySpec
- run_store: add sub_pattern column to DDL + idempotent migration;
  record_item accepts optional sub_pattern param
- Remove QuestionFamilySpec imports from generator_v2 and gates modules
- Update test call sites accordingly

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

app/question_gen/run_store.py

@@ -117,6 +117,7 @@ CREATE TABLE IF NOT EXISTS question_gen_items (
     skill_target      TEXT NOT NULL,
     attempt           INTEGER NOT NULL,
     question_text     TEXT NOT NULL,
+    sub_pattern       TEXT,
     gate_key_verify   TEXT,
     gate_blind_answer TEXT,
     gate_multi_true   TEXT,
@@ -176,6 +177,12 @@ class QuestionGenStore:
             self._conn.execute(idx_sql)
         self._conn.commit()
 
+        # 幂等迁移：为已有表加 sub_pattern 列
+        cols = {r[1] for r in self._conn.execute("PRAGMA table_info(question_gen_items)")}
+        if "sub_pattern" not in cols:
+            self._conn.execute("ALTER TABLE question_gen_items ADD COLUMN sub_pattern TEXT")
+            self._conn.commit()
+
     def record_run_start(self, run_id: str, git_sha: str, config_snapshot: str) -> None:
         """记录批次开始。
 
@@ -250,6 +257,7 @@ class QuestionGenStore:
         skill_target: str,
         attempt: int,
         question_text: str,
+        sub_pattern: str | None = None,
     ) -> None:
         """记录一道新生成的题目（初始状态 pending）。
 
@@ -273,14 +281,16 @@ class QuestionGenStore:
             当前重出轮次（1-based）。
         question_text : str
             题目文本。
+        sub_pattern : str | None
+            子模式标识（如有）。
         """
         now = datetime.now(tz=UTC).isoformat(timespec="seconds")
         self._conn.execute(
             """
             INSERT INTO question_gen_items
             (item_id, run_id, slot_id, video_id, family, task_type,
-             skill_target, attempt, question_text, created_at)
-            VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?, ?)
+             skill_target, attempt, question_text, sub_pattern, created_at)
+            VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?)
             """,
             (
                 item_id,
@@ -292,6 +302,7 @@ class QuestionGenStore:
                 skill_target,
                 attempt,
                 question_text,
+                sub_pattern,
                 now,
             ),
         )
@@ -400,21 +411,16 @@ class QuestionGenStore:
         )
 
     def load_progress(self) -> dict[str, str]:
-        """加载已完成 slot 的进度映射（用于断点续跑）。
+        """加载已接受 slot 的进度映射（用于断点续跑）。
 
-        从最近一次 running 状态的批次中，读取所有 final_status 非 pending 的 item，
-        聚合为 slot_id → "accepted"|"rejected" 映射。
-
-        若存在同一 slot_id 的多条记录（多次重出），取最终状态:
-        - 任一条 accepted → accepted
-        - 全部 rejected → rejected
+        从最近一次 running 状态的批次中，只读取 accepted 的 slot。
+        rejected 的 slot 不纳入 progress，以便重跑时重新尝试。
 
         Returns
         -------
         dict[str, str]
-            {slot_id: "accepted"|"rejected"} 映射。无进度时返回空 dict。
+            {slot_id: "accepted"} 映射。无进度时返回空 dict。
         """
-        # 取最近一次未结束的 run_id
         row = self._conn.execute(
             "SELECT run_id FROM question_gen_runs WHERE status='running' "
             "ORDER BY started_at DESC LIMIT 1",
@@ -425,19 +431,12 @@ class QuestionGenStore:
 
         run_id = row[0]
         rows = self._conn.execute(
-            "SELECT slot_id, final_status FROM question_gen_items "
-            "WHERE run_id=? AND final_status != 'pending'",
+            "SELECT DISTINCT slot_id FROM question_gen_items "
+            "WHERE run_id=? AND final_status='accepted'",
             (run_id,),
         ).fetchall()
 
-        progress: dict[str, str] = {}
-        for slot_id, status in rows:
-            if status == "accepted":
-                progress[slot_id] = "accepted"
-            elif slot_id not in progress:
-                progress[slot_id] = "rejected"
-
-        return progress
+        return {row[0]: "accepted" for row in rows}
 
     def close(self) -> None:
         """关闭数据库连接。"""