feat(economy): add vanity shop and harden economy money-safety

Vanity shop (/vanity): cosmetic badges/titles as a pure whale coin sink -
purchases burn coins (not credited to the house) and equip a badge shown on
/profile. New vanity_owned/vanity_active fields, schema sync, and tests.

Money-safety and robustness fixes from a codebase review:

- _parse_amount now rejects negative amounts. Every bet/give/request flows
  through it, so a negative value can no longer mint coins on a loss/transfer
  path that trusts the caller's sign (all call sites already guarded <= 0;
  this closes the source).
- do_blackjack_payout no longer raises on a DB failure. The stake was already
  deducted in do_blackjack_bet, so it now logs critical with the owed amount
  (for admin reconciliation) and returns db_error; all payout call sites render
  a clear "payout failed" notice instead of crashing the interaction.
- Instant "kohv" consumable now cancels the pending reminder DMs for the
  cooldowns it wipes (via new INSTANT_RESET_COMMANDS), so no stale/duplicate
  reminders fire.
- Renamed the misleadingly-named _refund_user_safe -> _debit_house_safe (it
  debits the house) and dropped its ignored first arg.
- Added __all__ to vanity.py and consumables.py so `import *` no longer leaks
  incidental imports into the economy namespace.
- Documented Kõrvaklapid's +25 coin daily bonus in README and DEV_NOTES.

Tests: blackjack payout DB-failure safety and INSTANT_RESET_COMMANDS lockstep.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_013VbAVsrZuYesea99mPMmPT

tests/test_vanity.py

@@ -0,0 +1,78 @@
+"""Tests for the vanity shop (cosmetic status sink, no gameplay effect)."""
+
+from core import economy
+
+from conftest import run
+
+UID = 7777
+
+
+def _fund(fake_pb, amount: int) -> None:
+    run(economy.get_user(UID))
+    fake_pb.record_for(UID)["balance"] = amount
+
+
+class TestBuy:
+    def test_buy_burns_coins_owns_and_equips(self, fake_pb):
+        _fund(fake_pb, 10_000)
+        cost = economy.VANITY["couch"]["cost"]
+        res = run(economy.do_vanity_select(UID, "couch"))
+        assert res["ok"] and res["action"] == "bought"
+        assert res["balance"] == 10_000 - cost
+        user = run(economy.get_user(UID))
+        assert "couch" in user["vanity_owned"]
+        assert user["vanity_active"] == "couch"
+        assert economy.vanity_badge(user) == ("🎮", "Sohvasõdur")
+
+    def test_coins_are_destroyed_not_sent_to_house(self, fake_pb, monkeypatch):
+        _fund(fake_pb, 10_000)
+        credited = []
+        monkeypatch.setattr(economy.house, "_credit_house", lambda amt: credited.append(amt))
+        run(economy.do_vanity_select(UID, "couch"))
+        assert credited == []          # nothing recirculated to the house
+
+    def test_insufficient_funds_rejected(self, fake_pb):
+        _fund(fake_pb, 100)
+        res = run(economy.do_vanity_select(UID, "legend"))
+        assert not res["ok"] and res["reason"] == "insufficient"
+        assert res["need"] == economy.VANITY["legend"]["cost"] - 100
+        assert run(economy.get_user(UID))["balance"] == 100   # unchanged
+
+    def test_banned_rejected(self, fake_pb):
+        _fund(fake_pb, 10_000)
+        fake_pb.record_for(UID)["eco_banned"] = True
+        res = run(economy.do_vanity_select(UID, "couch"))
+        assert not res["ok"] and res["reason"] == "banned"
+
+    def test_unknown_badge(self, fake_pb):
+        _fund(fake_pb, 10_000)
+        res = run(economy.do_vanity_select(UID, "nope"))
+        assert not res["ok"] and res["reason"] == "not_found"
+
+
+class TestEquip:
+    def test_equip_owned_is_free(self, fake_pb):
+        _fund(fake_pb, 20_000)
+        run(economy.do_vanity_select(UID, "couch"))     # buy + equip couch
+        run(economy.do_vanity_select(UID, "cables"))    # buy + equip cables
+        bal_before = run(economy.get_user(UID))["balance"]
+        res = run(economy.do_vanity_select(UID, "couch"))   # re-equip owned couch
+        assert res["ok"] and res["action"] == "equipped"
+        user = run(economy.get_user(UID))
+        assert user["vanity_active"] == "couch"
+        assert user["balance"] == bal_before            # no re-charge
+
+    def test_unequip_clears_badge(self, fake_pb):
+        _fund(fake_pb, 10_000)
+        run(economy.do_vanity_select(UID, "couch"))
+        res = run(economy.do_vanity_select(UID, economy.vanity.NONE_ID))
+        assert res["ok"] and res["action"] == "unequipped"
+        user = run(economy.get_user(UID))
+        assert user["vanity_active"] is None
+        assert economy.vanity_badge(user) is None
+        assert "couch" in user["vanity_owned"]          # still owned, just not worn
+
+
+def test_no_badge_by_default(fake_pb):
+    user = run(economy.get_user(UID))
+    assert economy.vanity_badge(user) is None