Implement full MVP: auth, HD wallet, Electrum client, deposits, bets, round/draw engine, payout, withdrawals, RBF, admin+audit

All 10 build-order stages complete and unit-tested (49 tests). Verified live on
mainnet: registration/address derivation, deposit crediting, a real 10 PLM bet
(broadcast + confirmed + change credited). A full round close->draw->payout
cycle was triggered live and was in progress at commit time. Withdrawal and RBF
bump are unit-tested but not yet exercised against a live broadcast. Known gaps
(scheduler doesn't resume mid-flight rounds after restart, payout has no retry,
no deployment setup, etc.) are documented in CLAUDE.md.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

tests/unit/test_rounds_service.py

@@ -0,0 +1,58 @@
+import pytest
+from sqlalchemy.ext.asyncio import async_sessionmaker, create_async_engine
+
+from app.db.base import Base
+from app.db.models import Round
+from app.rounds.service import get_active_round, open_new_round_if_needed
+
+
+@pytest.fixture
+async def session_factory():
+    engine = create_async_engine("sqlite+aiosqlite:///:memory:")
+    async with engine.begin() as conn:
+        await conn.run_sync(Base.metadata.create_all)
+    yield async_sessionmaker(engine, expire_on_commit=False)
+    await engine.dispose()
+
+
+async def test_opens_a_round_when_none_exists(session_factory):
+    async with session_factory() as session:
+        round_ = await open_new_round_if_needed(session)
+        await session.commit()
+        assert round_.status == "open"
+
+
+async def test_reuses_existing_open_round(session_factory):
+    async with session_factory() as session:
+        first = await open_new_round_if_needed(session)
+        await session.commit()
+        first_id = first.id
+
+    async with session_factory() as session:
+        second = await open_new_round_if_needed(session)
+        assert second.id == first_id
+
+
+@pytest.mark.parametrize("status", ["closing", "drawing", "paying_out"])
+async def test_does_not_open_new_round_while_previous_is_in_progress(session_factory, status):
+    async with session_factory() as session:
+        session.add(Round(status=status))
+        await session.commit()
+
+    async with session_factory() as session:
+        active = await get_active_round(session)
+        assert active is not None
+        assert active.status == status
+        # open_new_round_if_needed must return the in-progress round, not open a new one
+        returned = await open_new_round_if_needed(session)
+        assert returned.status == status
+
+
+async def test_opens_new_round_after_previous_is_closed(session_factory):
+    async with session_factory() as session:
+        session.add(Round(status="closed"))
+        await session.commit()
+
+    async with session_factory() as session:
+        round_ = await open_new_round_if_needed(session)
+        assert round_.status == "open"