feat(l1): APScheduler hourly cleanup job for abandoned L1 sessions

flip_stale_sessions flips L1WalkSession.status from 'active' to
'abandoned' for rows where last_step_at is older than 24h. Preserves the
row for audit; removes it from the L1 dashboard's 'Resume in progress'
widget. Runs hourly via APScheduler with max_instances=1 (Lesson 1).
Uses the admin session factory (no RLS context at startup).

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

backend/tests/test_l1_session_cleanup.py

@@ -0,0 +1,119 @@
+"""Tests for the l1_session_cleanup job."""
+import uuid
+from datetime import datetime, timedelta, timezone
+
+import pytest
+from sqlalchemy.ext.asyncio import AsyncSession
+
+from app.models.l1_walk_session import L1WalkSession
+from app.models.account import Account
+from app.models.user import User
+from app.services.l1_session_cleanup import flip_stale_sessions
+
+
+# ---------------------------------------------------------------------------
+# Helpers
+# ---------------------------------------------------------------------------
+
+async def _make_account(db: AsyncSession) -> Account:
+    import secrets
+    import string
+    code = "".join(secrets.choice(string.ascii_uppercase + string.digits) for _ in range(8))
+    a = Account(id=uuid.uuid4(), name="Test", display_code=code)
+    db.add(a)
+    await db.flush()
+    return a
+
+
+async def _make_user(db: AsyncSession, *, account_id: uuid.UUID) -> User:
+    u = User(
+        id=uuid.uuid4(),
+        email=f"user-{uuid.uuid4()}@example.com",
+        name="L1",
+        account_id=account_id,
+        account_role="l1_tech",
+        role="engineer",
+        is_active=True,
+    )
+    db.add(u)
+    await db.flush()
+    return u
+
+
+async def _make_session(
+    db: AsyncSession,
+    *,
+    account_id: uuid.UUID,
+    user_id: uuid.UUID,
+    status: str = "active",
+    last_step_at: datetime | None = None,
+) -> L1WalkSession:
+    now = datetime.now(timezone.utc)
+    session = L1WalkSession(
+        id=uuid.uuid4(),
+        account_id=account_id,
+        created_by_user_id=user_id,
+        ticket_id="t",
+        ticket_kind="internal",
+        session_kind="adhoc",
+        status=status,
+        started_at=now,
+        last_step_at=last_step_at or now,
+    )
+    db.add(session)
+    await db.flush()
+    return session
+
+
+# ---------------------------------------------------------------------------
+# Tests
+# ---------------------------------------------------------------------------
+
+@pytest.mark.asyncio
+async def test_flip_stale_sessions_only_affects_old_active_rows(test_db: AsyncSession):
+    account = await _make_account(test_db)
+    user = await _make_user(test_db, account_id=account.id)
+
+    # 1. Stale active (>24h ago) — should flip
+    stale = await _make_session(
+        test_db, account_id=account.id, user_id=user.id,
+        status="active",
+        last_step_at=datetime.now(timezone.utc) - timedelta(hours=25),
+    )
+    # 2. Fresh active (1h ago) — should stay active
+    fresh = await _make_session(
+        test_db, account_id=account.id, user_id=user.id,
+        status="active",
+        last_step_at=datetime.now(timezone.utc) - timedelta(hours=1),
+    )
+    # 3. Already-resolved (old) — should stay resolved, not flip
+    already_resolved = await _make_session(
+        test_db, account_id=account.id, user_id=user.id,
+        status="resolved",
+        last_step_at=datetime.now(timezone.utc) - timedelta(hours=48),
+    )
+    await test_db.commit()
+
+    count = await flip_stale_sessions(test_db)
+    assert count == 1
+
+    await test_db.refresh(stale)
+    await test_db.refresh(fresh)
+    await test_db.refresh(already_resolved)
+    assert stale.status == "abandoned"
+    assert fresh.status == "active"
+    assert already_resolved.status == "resolved"
+
+
+@pytest.mark.asyncio
+async def test_flip_stale_sessions_returns_zero_when_none_stale(test_db: AsyncSession):
+    account = await _make_account(test_db)
+    user = await _make_user(test_db, account_id=account.id)
+    await _make_session(
+        test_db, account_id=account.id, user_id=user.id,
+        status="active",
+        last_step_at=datetime.now(timezone.utc) - timedelta(hours=1),
+    )
+    await test_db.commit()
+    count = await flip_stale_sessions(test_db)
+    assert count == 0