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

strings/commands.py

@@ -74,6 +74,7 @@ CMD: dict[str, str] = {
     "patchnotes":     "Vaata TipiBOTi viimaseid muudatusi ja uuendusi",
     "quests":         "Vaata oma päeva- ja nädalaülesandeid ning nõua auhinnad",
     "consumables":    "Sirvi ja osta turgutusi (korduvostetavad boostid)",
+    "vanity":         "Staatusepood - osta ja kanna kosmeetilisi tiitleid",
 }
 
 # ---------------------------------------------------------------------------
@@ -92,6 +93,7 @@ OPT: dict[str, str] = {
     "give_summa":         "Kui palju annad? ('all' = kogu saldo)",
     "buy_ese":            "Eseme nimi (vaata /shop)",
     "consumable_ese":     "Turgutus, mida osta (tühjaks jättes näeb menüüd)",
+    "vanity_ese":         "Tiitel, mida osta või kanda (tühjaks jättes näeb poodi)",
     "rps_panus":          "Valikuline TipiCOINide panus ('all' = kogu saldo)",
     "rps_vastane":        "Väljakutse teisele mängijale (PvP)",
     "slots_panus":        "Panus TipiCOINides ('all' = kogu saldo)",