Add version system, tax tracking, lottery winner DMs, fmtEuro, audit fixes

- Version system: per-plugin versions via Versioned interface, crash_log and
  version_history DB tables, !version command, crash stats in !botinfo
- Tax tracking: tax_ledger table, trackTaxPaid across all communityTax and
  communityPotAdd sites, tax paid display in !stats and !superstatsexplusalpha
- Lottery: DM winners with winning ticket details and matched numbers bolded
- fmtEuro: generic currency formatter with thousand separators across all
  economy display paths
- Audit fixes: streak_decayed column for Streak Survivor achievement,
  combat_narrative empty-phase guard, crafting success rate integer division,
  RecordCrash nil-DB guard

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

internal/plugin/uno_multi.go

@@ -2564,7 +2564,8 @@ func (p *UnoPlugin) multiPlayerWins2(game *unoMultiGame, winner *unoMultiPlayer)
 		}
 	}
 	totalPot := game.ante * float64(humanCount+game.botAntes)
-	p.euro.Credit(winner.userID, totalPot, "uno_multi_win")
+	net, _ := communityTax(winner.userID, totalPot, 0.05)
+	p.euro.Credit(winner.userID, net, "uno_multi_win")
 
 	p.recordMultiGame(game, winner.userID, "sudden_death_win")
 	p.cleanupMultiGame(game)
@@ -2614,9 +2615,10 @@ func (p *UnoPlugin) multiPlayerWins(game *unoMultiGame, winner *unoMultiPlayer)
 		}
 	}
 	totalPot := game.ante * float64(humanCount+game.botAntes)
+	net, _ := communityTax(winner.userID, totalPot, 0.05)
 
 	name := p.DisplayName(winner.userID)
-	p.euro.Credit(winner.userID, totalPot, "uno_multi_win")
+	p.euro.Credit(winner.userID, net, "uno_multi_win")
 
 	p.SendMessage(game.roomID, fmt.Sprintf(
 		"🎉 **%s wins Multiplayer UNO!**\nPot: €%d | Turns: %d\n\n%s",