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

commands/economy_support_commands.py

@@ -224,6 +224,10 @@ def register_economy_support_commands(
 
         cons = res["consumable"]
         if res["instant"]:
+            # Kohv wiped these cooldowns, so any reminder DM already scheduled for
+            # them is now stale - cancel it (the next command run reschedules).
+            for cmd in economy.INSTANT_RESET_COMMANDS:
+                cancel_reminder_task(interaction.user.id, cmd)
             desc = S.CONSUMABLES_UI["bought_instant"].format(balance=coin(res["balance"]))
         else:
             key = "bought_extended" if res["extended"] else "bought_buff"
@@ -238,6 +242,75 @@ def register_economy_support_commands(
         )
         await interaction.response.send_message(embed=embed)
 
+    # -- /vanity ------------------------------------------------------------
+    def _vanity_embed(user_data: dict) -> discord.Embed:
+        owned = set(user_data.get("vanity_owned") or [])
+        active = user_data.get("vanity_active")
+        embed = discord.Embed(
+            title=S.VANITY_UI["title"],
+            description=S.VANITY_UI["desc"].format(bal=coin(user_data.get("balance", 0))),
+            color=0xF4C430,
+        )
+        for vid, v in economy.VANITY.items():
+            if vid == active:
+                status = S.VANITY_UI["line_active"]
+            elif vid in owned:
+                status = S.VANITY_UI["line_owned"]
+            else:
+                status = f"{v['cost']} {economy.COIN}"
+            embed.add_field(
+                name=f"{v['emoji']} {v['name']}  ·  {status}",
+                value=S.VANITY_UI["entry_title"].format(title=v["title"]),
+                inline=False,
+            )
+        embed.set_footer(text=S.VANITY_UI["footer"])
+        return embed
+
+    @tree.command(name="vanity", description=S.CMD["vanity"])
+    @app_commands.describe(ese=S.OPT["vanity_ese"])
+    @app_commands.choices(
+        ese=[
+            app_commands.Choice(name=f"{v['emoji']} {v['title']} ({v['cost']} TipiCOINi)", value=vid)
+            for vid, v in economy.VANITY.items()
+        ]
+        + [app_commands.Choice(name=S.VANITY_UI["none_choice"], value=economy.vanity.NONE_ID)]
+    )
+    async def cmd_vanity(
+        interaction: discord.Interaction,
+        ese: app_commands.Choice[str] | None = None,
+    ):
+        if ese is None:
+            data = await economy.get_user(interaction.user.id)
+            await interaction.response.send_message(
+                embed=_vanity_embed(data), ephemeral=True
+            )
+            return
+
+        res = await economy.do_vanity_select(interaction.user.id, ese.value)
+        if not res["ok"]:
+            if res["reason"] == "banned":
+                await interaction.response.send_message(S.MSG_BANNED, ephemeral=True)
+            elif res["reason"] == "insufficient":
+                await interaction.response.send_message(
+                    S.ERR["broke_need"].format(need=coin(res["need"])), ephemeral=True
+                )
+            else:
+                await interaction.response.send_message(S.ERR["item_not_found"], ephemeral=True)
+            return
+
+        action = res["action"]
+        if action == "unequipped":
+            await interaction.response.send_message(S.VANITY_UI["unequipped"], ephemeral=True)
+            return
+        v = res["vanity"]
+        if action == "bought":
+            msg = S.VANITY_UI["bought"].format(
+                emoji=v["emoji"], title=v["title"], balance=coin(res["balance"])
+            )
+        else:
+            msg = S.VANITY_UI["equipped"].format(emoji=v["emoji"], title=v["title"])
+        await interaction.response.send_message(msg)
+
     class RemindersSelect(discord.ui.Select):
         def __init__(self, user_id: int, current: list[str]):
             self.user_id = user_id