fix(scheduler): daily slot off-plan + cross-midnight resume (#8)

- Cross-midnight: unfinished yesterday seals ASAP with yesterday's stat_date;
  force seal ignores today's snapshot_at gate when stat_date < today.
- Off-plan already_completed: compare completion started_at (not finished_at)
  to today's planned slot; earlier → still run at slot for all daily tasks.
- Cold start: bootstrap task:state from task:last / seed markers.
- ensure_pending: do not glue new due onto a different day's unfinished state.
- run_if_needed(force): keep_scraped True for seal, False for CLI --force.
- Scheduler due_reader: pick up disk due_at each loop (seed→evening seal).

tests/test_task_state.py

@@ -20,6 +20,7 @@ from reaction_board.task_state import (  # noqa: E402
     STATUS_FAILED,
     STATUS_PENDING,
     STATUS_RUNNING,
+    bootstrap_from_last,
     ensure_pending,
     load_state,
     mark_deferred,
@@ -251,6 +252,133 @@ def test_fail_or_defer_preserves_progress():
             db.close()
 
 
+
+def test_bootstrap_from_last_fail_due_soon():
+    """A: 仅有 task:last 失败、无 state → 回填 failed 且 due_at 可立刻补跑。"""
+    with tempfile.TemporaryDirectory() as tmp:
+        db, repo = _repo(tmp)
+        try:
+            now = datetime(2026, 11, 3, 12, 0, tzinfo=SHANGHAI_TZ).timestamp()
+            wall = next_daily_run(now, "23:15")
+            repo.kv_set(
+                "task:last:snapshot",
+                json.dumps({
+                    "name": "snapshot",
+                    "ok": False,
+                    "skipped": False,
+                    "started_at": int(now - 600),
+                    "finished_at": int(now - 500),
+                    "error": "boom",
+                    "summary": {"stat_date": "2026-11-03"},
+                }, ensure_ascii=False),
+            )
+            assert load_state(repo, "snapshot") is None
+            boot = bootstrap_from_last(
+                repo, "snapshot", wall_due_at=wall, now=now, retry_seconds=300.0,
+            )
+            assert boot is not None
+            assert boot.status == STATUS_FAILED
+            assert boot.stat_date == "2026-11-03"
+            assert boot.due_at <= now
+            nxt = startup_next_run(
+                repo, "snapshot", wall_due_at=wall, now=now, slot_hhmm="23:15",
+            )
+            assert nxt <= now
+            assert nxt != wall
+        finally:
+            db.close()
+
+
+def test_ensure_pending_does_not_glue_yesterday_stat_date():
+    """B: 昨天未完成保留；不得把今晚 due 粘到昨天的 stat_date 上。"""
+    with tempfile.TemporaryDirectory() as tmp:
+        db, repo = _repo(tmp)
+        try:
+            now = datetime(2026, 11, 3, 0, 10, tzinfo=SHANGHAI_TZ).timestamp()
+            yday_due = now - 60
+            ensure_pending(
+                repo, "snapshot", due_at=yday_due,
+                stat_date="2026-11-02", now=now - 120,
+            )
+            tonight = datetime(2026, 11, 3, 23, 15, tzinfo=SHANGHAI_TZ).timestamp()
+            # seed 想挂今晚：不得冲掉昨天未完成
+            kept = ensure_pending(
+                repo, "snapshot", due_at=tonight,
+                stat_date="2026-11-03", now=now,
+            )
+            assert kept.stat_date == "2026-11-02"
+            assert kept.due_at == yday_due
+            assert resume_stat_date(
+                repo, "snapshot", fallback="2026-11-03",
+            ) == "2026-11-02"
+        finally:
+            db.close()
+
+
+def test_cross_midnight_mid_seal_resumes_yesterday():
+    """规则1 / B: 23:15 崩溃 → 00:10 重启续跑昨天，due 立刻可跑。"""
+    with tempfile.TemporaryDirectory() as tmp:
+        db, repo = _repo(tmp)
+        try:
+            crash = datetime(2026, 11, 2, 23, 40, tzinfo=SHANGHAI_TZ).timestamp()
+            mark_running(
+                repo, "snapshot", stat_date="2026-11-02", now=crash,
+                progress={"done": 3, "total": 10},
+            )
+            repo.kv_set("snapshot:seeded:2026-11-02", "1")
+            restart = datetime(2026, 11, 3, 0, 10, tzinfo=SHANGHAI_TZ).timestamp()
+            wall = next_daily_run(restart, "23:15")
+            nxt = startup_next_run(
+                repo, "snapshot", wall_due_at=wall, now=restart, slot_hhmm="23:15",
+            )
+            assert nxt <= restart
+            assert resume_stat_date(
+                repo, "snapshot", fallback="2026-11-03",
+            ) == "2026-11-02"
+            state = load_state(repo, "snapshot")
+            assert state is not None
+            assert state.status == STATUS_PENDING
+            assert state.progress == {"done": 3, "total": 10}
+        finally:
+            db.close()
+
+
+def test_scheduler_due_reader_picks_up_enqueued_seal():
+    """D: 同进程 seed 写盘 due_at=now 后，下一轮 run_due 须跑 seal。"""
+    with tempfile.TemporaryDirectory() as tmp:
+        db, repo = _repo(tmp)
+        try:
+            now = datetime(2026, 11, 3, 23, 20, tzinfo=SHANGHAI_TZ).timestamp()
+            # snapshot 原 next_run 挂次日；盘上被 enqueue 成 now
+            tomorrow = next_daily_run(now, "23:15")
+            calls = []
+
+            def run_snap():
+                calls.append("snap")
+                return None
+
+            def due_reader(name: str):
+                st = load_state(repo, name)
+                return float(st.due_at) if st and st.due_at else None
+
+            clock = [now]
+            sched = Scheduler(
+                [ScheduledTask("snapshot", 86400.0, run_snap, next_run=tomorrow)],
+                clock=lambda: clock[0],
+                due_reader=due_reader,
+            )
+            assert sched.run_due() == []
+            assert calls == []
+            ensure_pending(
+                repo, "snapshot", due_at=now, stat_date="2026-11-03", now=now,
+            )
+            results = sched.run_due()
+            assert len(results) == 1
+            assert calls == ["snap"]
+        finally:
+            db.close()
+
+
 def main_test():
     test_restart_mid_run_resumes_same_stat_date()
     test_seeded_before_snapshot_at_does_not_force_run()
@@ -259,6 +387,10 @@ def main_test():
     test_done_writes_next_due_and_blocks_until_then()
     test_no_state_falls_back_to_wall_clock()
     test_fail_or_defer_preserves_progress()
+    test_bootstrap_from_last_fail_due_soon()
+    test_ensure_pending_does_not_glue_yesterday_stat_date()
+    test_cross_midnight_mid_seal_resumes_yesterday()
+    test_scheduler_due_reader_picks_up_enqueued_seal()
     print("OK: task_state persistence / resume / due_at gates")