test: booking-flow, availability, and #4 concurrency regression

16 tests, run under the LNbits pytest env (spirekeeper pattern: monkeypatch
crud/invoice, drive async via asyncio.run — no live DB/wallet):

- test_availability: half-open overlap semantics (back-to-back stays OK),
  and is_available blocking on held/confirmed bookings + manual blocks.
- test_booking_flow: canonical amount_sat, awaiting_payment transition,
  min-nights guard, and hold-release (declined) on InvoiceError.
- test_atomic_hold: the #4 regression — two concurrent same-date requests
  yield exactly one hold + one conflict; non-overlapping both succeed. The
  fakes yield mid-check to open the race window, so the test fails without
  the per-room lock (verified by neutering it) and passes with it.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_019VUQCfdqiLSsFS2jcGnaFD

tests/conftest.py

@@ -0,0 +1,88 @@
+"""Pytest configuration + factories for the chatelet test suite.
+
+Following the spirekeeper pattern: unit tests isolate the function under
+test by monkeypatching the crud / lnbits calls it makes and driving async
+functions with `asyncio.run(...)`, so no live LNbits DB or wallet is needed.
+The `loguru_capture` fixture is here for the same reason spirekeeper needs
+it — loguru binds sys.stderr at import, before capsys wraps it.
+"""
+
+from typing import Generator, List
+
+import pytest
+from loguru import logger
+
+from ..models import (
+    BookingRequestData,
+    CreateRoomData,
+    Room,
+    RoomStatus,
+)
+
+
+@pytest.fixture(autouse=True)
+def _reset_room_locks():
+    """Each test drives its own `asyncio.run` loop, but `services._room_locks`
+    is module-level — a lock created in one test's loop would raise
+    'bound to a different event loop' when reused in the next. Clear the
+    registry around every test so locks are recreated in the active loop.
+    (Production is unaffected: LNbits runs one long-lived loop.)"""
+    from .. import services
+
+    services._room_locks.clear()
+    yield
+    services._room_locks.clear()
+
+
+@pytest.fixture
+def loguru_capture() -> Generator[List[str], None, None]:
+    captured: List[str] = []
+    handler_id = logger.add(
+        captured.append, level="WARNING", format="{level} {message}"
+    )
+    yield captured
+    logger.remove(handler_id)
+
+
+# --- factories -------------------------------------------------------------
+
+
+def make_room(
+    room_id: str = "room1",
+    *,
+    wallet: str = "wallet1",
+    currency: str = "sat",  # "sat" so pricing skips the FX call in tests
+    price: float = 100.0,
+    min_nights: int = 1,
+    max_guests: int = 2,
+    status: RoomStatus = RoomStatus.active,
+) -> Room:
+    return Room(
+        **CreateRoomData(
+            wallet=wallet,
+            title="Tower Room",
+            price_amount=price,
+            price_currency=currency,
+            min_nights=min_nights,
+            max_guests=max_guests,
+        ).dict(),
+        id=room_id,
+        status=status,
+    )
+
+
+def make_request(
+    room_id: str = "room1",
+    *,
+    guest: str = "npub_guest",
+    check_in: str = "2026-08-01",
+    check_out: str = "2026-08-04",
+    num_guests: int = 1,
+) -> BookingRequestData:
+    return BookingRequestData(
+        room_id=room_id,
+        guest_pubkey=guest,
+        check_in=check_in,
+        check_out=check_out,
+        num_guests=num_guests,
+    )