Fix money-safety bugs in economy (heist, blackjack, bail)

Multi-agent audit of the money-moving economy modules surfaced three
confirmed correctness bugs. All three are fixed here with regression tests.

heist (core/economy/heist.py):
- `house = await get_user(house.HOUSE_ID)` shadowed the imported `house`
  module for the whole function, so `house.HOUSE_ID` raised UnboundLocalError
  on every successful heist (win payout was entirely dead) and on the
  fail-path compensation branch. Rename the local to `house_rec`.
- Un-shadowing exposed a latent mint: the pot was floored at 300 but the
  house was debited only min(total, balance), so a poor house paid out more
  than it lost. Cap the pot at the balance and debit exactly what is paid
  (house debit == sum of payouts). No mint, no leak.
- Add the missing `_is_jailed` import (do_heist_check referenced it unimported).

blackjack (commands/economy_games_commands.py):
- Button callbacks had no reentrancy guard; discord.py dispatches each click
  as its own task, so double-clicking Stand within the dealer-reveal window
  paid out twice (mint), and double-clicking Double/Split deducted the extra
  bet twice. Add a synchronous `_busy` guard (matching the existing RpsGame
  idiom) on all four callbacks plus a `_resolved` idempotency flag on
  settlement, so a game can only pay out once.

bail (core/economy/jail.py, commands/economy_extra_commands.py):
- do_bail only checked balance, never jail state; a double-click or a stale
  BailView from a re-run /jailbreak charged bail twice, destroying coins (bail
  is a pure sink). Make do_bail a no-op when the user is not jailed, and add a
  UI reentrancy guard + "already free" message.

Tests: 47 passed (4 new regression tests covering heist coin-conservation and
bail idempotency).

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

tests/test_money_safety_fixes.py

@@ -0,0 +1,91 @@
+"""Regression tests for the money-safety audit fixes.
+
+Covers the two pure-logic fixes:
+- heist payout conserves coins (no minting when the house is poor) and the win
+  path no longer crashes on the shadowed `house` local.
+- do_bail is idempotent: a jailed user can only be charged once per sentence, so
+  a double-click or a stale BailView cannot destroy coins with a second fine.
+"""
+
+from datetime import datetime, timedelta, timezone
+
+from core import economy
+
+from conftest import run
+
+UID = 111
+OTHER = 222
+HOUSE = 999
+
+
+def _fixed_now(monkeypatch, dt: datetime):
+    monkeypatch.setattr(economy.store, "_clock", lambda: dt)
+    return dt
+
+
+class TestHeistConservation:
+    def _setup_house(self, fake_pb, monkeypatch, balance: int):
+        monkeypatch.setattr(economy.house, "HOUSE_ID", HOUSE)
+        monkeypatch.setattr(economy.house, "_house_pb_id", None)
+        run(economy.get_user(HOUSE))
+        fake_pb.record_for(HOUSE)["balance"] = balance
+
+    def test_poor_house_win_does_not_mint(self, fake_pb, monkeypatch):
+        # Poor house is the case the pre-fix code minted from: the desired pot
+        # (floored at 300) exceeded the balance, so payouts outran the debit.
+        self._setup_house(fake_pb, monkeypatch, balance=100)
+        run(economy.get_user(UID))
+        run(economy.get_user(OTHER))
+
+        house_before = fake_pb.record_for(HOUSE)["balance"]
+        res = run(economy.do_heist_resolve([UID, OTHER], True))  # must not raise
+        assert res["ok"] and res["success"]
+
+        house_after = fake_pb.record_for(HOUSE)["balance"]
+        gains = fake_pb.record_for(UID)["balance"] + fake_pb.record_for(OTHER)["balance"]
+        # Coin conservation: the house loses exactly what the players gain.
+        assert house_before - house_after == gains
+        assert house_after >= 0
+        assert res["payout_each"] * 2 == gains
+
+    def test_rich_house_win_pays_out_and_conserves(self, fake_pb, monkeypatch):
+        self._setup_house(fake_pb, monkeypatch, balance=100_000)
+        run(economy.get_user(UID))
+        run(economy.get_user(OTHER))
+
+        house_before = fake_pb.record_for(HOUSE)["balance"]
+        res = run(economy.do_heist_resolve([UID, OTHER], True))
+        assert res["ok"] and res["payout_each"] > 0
+
+        house_after = fake_pb.record_for(HOUSE)["balance"]
+        gains = fake_pb.record_for(UID)["balance"] + fake_pb.record_for(OTHER)["balance"]
+        assert house_before - house_after == gains
+
+
+class TestBailIdempotency:
+    def _jail(self, fake_pb, now, balance: int):
+        run(economy.get_user(UID))
+        rec = fake_pb.record_for(UID)
+        rec["balance"] = balance
+        rec["jailed_until"] = (now + timedelta(minutes=30)).isoformat()
+
+    def test_second_bail_when_free_is_noop(self, fake_pb, monkeypatch):
+        now = _fixed_now(monkeypatch, datetime(2026, 7, 25, 12, tzinfo=timezone.utc))
+        self._jail(fake_pb, now, balance=1000)
+
+        first = run(economy.do_bail(UID))
+        assert first["ok"]
+        bal_after_first = fake_pb.record_for(UID)["balance"]
+        assert bal_after_first < 1000  # a fine was charged
+        assert fake_pb.record_for(UID)["jailed_until"] is None  # freed
+
+        # A double-click / stale view fires do_bail again while already free.
+        second = run(economy.do_bail(UID))
+        assert not second["ok"] and second["reason"] == "not_jailed"
+        assert fake_pb.record_for(UID)["balance"] == bal_after_first  # no second charge
+
+    def test_bail_charges_once_for_a_real_sentence(self, fake_pb, monkeypatch):
+        now = _fixed_now(monkeypatch, datetime(2026, 7, 25, 12, tzinfo=timezone.utc))
+        self._jail(fake_pb, now, balance=1000)
+        res = run(economy.do_bail(UID))
+        assert res["ok"] and res["fine"] >= economy.MIN_BAIL