Add bot defeat tracking, audit fixes, and README UNO section

Add !twinbeeboard command (GogoBee's trophy wall) with unified
bot_defeats table tracking losses across Blackjack, UNO solo, and
UNO multiplayer. Fix No Mercy audit bugs: wild card color choice
routing, bot Color Roulette double-advance, missing DM notifications
for roulette victims and 7-0 swap targets, autoplay Color Roulette
effect. Remove dead code. Update README with full UNO documentation.

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

internal/plugin/uno_multi.go

@@ -2367,6 +2367,11 @@ func (p *UnoPlugin) multiBotWins(game *unoMultiGame) {
 		"💀 **%s wins Multiplayer UNO!**\n€%d goes to the community pot.\n\n%s",
 		bn, int(totalPot), pickCommentary("bot_win")))
 
+	for _, pl := range game.players {
+		if !pl.isBot {
+			recordBotDefeat(pl.userID, "uno_multi")
+		}
+	}
 	p.recordMultiGame(game, id.UserID("bot"), "bot_win")
 	p.cleanupMultiGame(game)
 }