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

docs/DEV_NOTES.md

@@ -116,7 +116,7 @@ All economy state is stored in **PocketBase** (`economy_users` collection). `cor
 
 | Command | Cooldown | Base Earn | Notes |
 |---|---|---|---|
-| `/daily` | 20h (18h w/ korvaklapid) | 150⬡ | ×streak multiplier, ×2 w/ lan_pass, +5% interest w/ gaming_laptop |
+| `/daily` | 20h (18h w/ korvaklapid) | 150⬡ | ×streak multiplier, ×2 w/ lan_pass, +25⬡ w/ korvaklapid, +5% interest w/ gaming_laptop |
 | `/work` | 1h (40min w/ monitor) | 15-75⬡ | ×1.5 w/ gaming_hiir, ×1.25 w/ reguleeritav_laud, ×3 30% chance w/ energiajook |
 | `/beg` | 5min (3min w/ hiirematt) | 10-40⬡ | ×2 w/ klaviatuur |
 | `/crime` | 2h | 200-500⬡ win | 60% success (75% w/ cat6), +30% w/ mikrofon; fail = fine + jail |