feat(economy): add /consumables shop of repeatable, expiring boosts

The economy had many coin faucets but almost no sinks: the /shop is
one-time ownership, and gambling/rob fines route to the house (which
players drain back via jackpots and heists), so they recirculate rather
than destroy coins. Result: steady inflation.

Add a consumables shop as a true recurring sink - buying destroys the
coins and grants a temporary boost, so there's always something to spend
on after gear is maxed:

  - Energiajook XL (500) - 1h of 2x earnings on /work, /beg, /crime
  - XP jook (500)        - 1h of 2x EXP
  - Kohv (300)           - instantly clears all cooldowns

Timed buffs live in a new active_buffs field ({kind: expiry_iso}), pruned
on read; rebuying extends the timer. Effects hook where they belong:
earn_mult in income.do_work/do_beg/do_crime, exp_buff_mult in
levels.award_exp; kohv is self-contained. New /consumables command browses
the menu (with active buffs) or buys a boost. Covered by 9 tests.

Note: active_buffs is a new PocketBase field - run
scripts/sync_pb_schema.py before deploying or buffs won't persist.

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

commands/economy_support_commands.py

@@ -163,6 +163,81 @@ def register_economy_support_commands(
         await interaction.response.send_message(embed=embed, view=view)
         view.message = await interaction.original_response()
 
+    # -- /consumables -------------------------------------------------------
+    def _consumables_embed(user_data: dict) -> discord.Embed:
+        embed = discord.Embed(
+            title=S.CONSUMABLES_UI["title"],
+            description=S.CONSUMABLES_UI["desc"].format(bal=coin(user_data["balance"])),
+            color=0xF4C430,
+        )
+        active = economy.active_buffs(user_data)
+        if active:
+            lines = [
+                S.CONSUMABLES_UI["buff_line"].format(
+                    name=S.CONSUMABLES_UI[f"kind_{kind}"],
+                    time=economy.format_td(economy.buff_remaining(user_data, kind)),
+                )
+                for kind in active
+            ]
+            buff_value = "\n".join(lines)
+        else:
+            buff_value = S.CONSUMABLES_UI["active_none"]
+        embed.add_field(name=S.CONSUMABLES_UI["active_header"], value=buff_value, inline=False)
+        for cons in economy.CONSUMABLES.values():
+            embed.add_field(
+                name=f"{cons['emoji']} {cons['name']}  ·  {cons['cost']} {economy.COIN}",
+                value=cons["description"],
+                inline=False,
+            )
+        return embed
+
+    @tree.command(name="consumables", description=S.CMD["consumables"])
+    @app_commands.describe(ese=S.OPT["consumable_ese"])
+    @app_commands.choices(
+        ese=[
+            app_commands.Choice(name=f"{c['name']} ({c['cost']} TipiCOINi)", value=cid)
+            for cid, c in economy.CONSUMABLES.items()
+        ]
+    )
+    async def cmd_consumables(
+        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=_consumables_embed(data), ephemeral=True
+            )
+            return
+
+        res = await economy.do_buy_consumable(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
+
+        cons = res["consumable"]
+        if res["instant"]:
+            desc = S.CONSUMABLES_UI["bought_instant"].format(balance=coin(res["balance"]))
+        else:
+            key = "bought_extended" if res["extended"] else "bought_buff"
+            desc = S.CONSUMABLES_UI[key].format(
+                time=economy.format_td(res["remaining"]),
+                balance=coin(res["balance"]),
+            )
+        embed = discord.Embed(
+            title=S.CONSUMABLES_UI["bought_title"].format(emoji=cons["emoji"], name=cons["name"]),
+            description=desc,
+            color=0x57F287,
+        )
+        await interaction.response.send_message(embed=embed)
+
     class RemindersSelect(discord.ui.Select):
         def __init__(self, user_id: int, current: list[str]):
             self.user_id = user_id