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>

core/economy/heist.py

@@ -7,7 +7,7 @@ import random
 from .. import pb_client
 from ..pb_client import DatabaseError
 from . import house
-from .store import HEIST_JAIL, _commit, _now, _txn, _user_lock, get_user
+from .store import HEIST_JAIL, _commit, _is_jailed, _now, _txn, _user_lock, get_user
 from .house import _credit_house, _refund_house_safe, _refund_user_safe
 
 
@@ -39,19 +39,25 @@ async def do_heist_resolve(user_ids: list[int], success: bool) -> dict:
     failed_users: list[int] = []
 
     if success and house.HOUSE_ID is not None:
+        # NB: use a distinct local name - assigning to `house` here would shadow
+        # the imported module for the whole function and break `house.HOUSE_ID`.
         try:
-            house = await get_user(house.HOUSE_ID)
+            house_rec = await get_user(house.HOUSE_ID)
             pct = random.uniform(0.20, 0.55)
-            total = max(300, int(house["balance"] * pct))
-            payout_each = total // len(user_ids)
-            # Atomic decrement (capped at the balance we read) instead of a full
-            # record commit, so concurrent _credit_house increments aren't lost.
-            debit = min(total, house["balance"])
+            # Never promise more than the house actually holds: the desired pot
+            # is capped at the current balance, and each share is floored, so the
+            # amount debited equals the amount paid out (no minting, no leak).
+            pot = min(max(300, int(house_rec["balance"] * pct)), house_rec["balance"])
+            pot = max(0, pot)
+            payout_each = pot // len(user_ids)
+            debit = payout_each * len(user_ids)
+            # Atomic decrement instead of a full record commit, so concurrent
+            # _credit_house increments aren't lost.
             if debit > 0:
-                await pb_client.update_record(house["_pb_id"], {"balance-": debit})  # type: ignore[typeddict-item]
+                await pb_client.update_record(house_rec["_pb_id"], {"balance-": debit})  # type: ignore[typeddict-item]
         except DatabaseError:
             return {"ok": False, "reason": "db_error"}
-        _txn("HEIST_HOUSE", change=f"-{debit}", house_bal=house["balance"] - debit)
+        _txn("HEIST_HOUSE", change=f"-{debit}", house_bal=house_rec["balance"] - debit)
 
     for uid in user_ids:
         async with _user_lock(uid):