Add rival duels, babysitting service, multilingual !define, economy tuning

Rival System:
- RPS-based duels between combat level 5+ players (best of 3, ties re-prompt)
- Stakes scale with level, split 50/50 between winner and community pot
- 3-4 day randomized challenge interval, 7-day same-pair cooldown
- 24h response window with auto-forfeit
- Full flavor text pools, character sheet integration, !adventure rivals

Babysitting Service:
- Weekly/monthly auto-play service targeting weakest skill
- Babysitter rerolls death, claims items, credits gold and XP
- Rivals automatically declined during service
- End-of-service summary with diaper report

Revive fixes:
- On-demand revive in handleMenu, parseAndResolveChoice, handleStatus
- Morning DM respawn check now runs before babysit interception
- Players no longer stuck dead after DeadUntil expires mid-day

Other changes:
- Multilingual !define searches all DreamDict languages by default
- TwinBee empty haul now shows "jackshit" instead of blank
- Wordle solve payouts increased (e.g. 1-guess: €100 -> €500)
- Per-message euro payouts doubled across all tiers
- Audit fixes: user locks on RPS/babysit handlers, TOCTOU on gold
  transfers, dead code removal, deprecated strings.Title replaced,
  error logging on silent failures

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

README.md

@@ -611,7 +611,7 @@ A multi-tier combat gauntlet independent of the daily adventure action. Fight th
 | Command | Description |
 |---------|-------------|
 | `!wiki <topic>` | Wikipedia summary |
-| `!define <word>` | Dictionary definition (includes antonyms from DreamDict when available) |
+| `!define <word> [lang]` | Dictionary definition — searches all languages via DreamDict by default, or specify one (en/fr/pt-PT/zh). Includes antonyms when available. Falls back to free dictionary API for English if DreamDict is unavailable. |
 | `!urban <term>` | Urban Dictionary |
 | `!translate <word> [lang]` | Cross-language word lookup (en/fr/pt-PT, auto-detects source) |
 | `!antonym <word> [lang]` | Antonyms for a word (en/fr/pt-PT/zh) |