Add forex plugin, stability fixes, and async HTTP dispatch

- Add forex plugin (Frankfurter v2 API) with rate lookups, analysis,
  DM-based alerts, and daily cron poll. Backfills 1 year of history
  on startup for moving averages and buy signal scoring.

- Fix bot hang caused by SQLite lock contention in reminder polling:
  rows cursor was held open while writing to the same DB. Collect
  results first, close cursor, then process. Same fix in milkcarton.

- Add sync retry loop so the bot reconnects after network drops
  instead of silently exiting. StopSync() for clean Ctrl+C shutdown.

- Add panic recovery to all dispatch, syncer, and cron paths.

- Make all HTTP-calling plugin commands async (goroutines) so a slow
  or dead external API cannot block the message dispatch pipeline.
  Affects: lookup, stocks, forex, anime, movies, concerts, gaming,
  retro, wotd, urls, howami.

- Extract DisplayName to Base, add db.Exec helper, convert silent
  error discards across the codebase.

- Fix UNO mercy-kill bug (eliminated bot continues playing), adventure
  DM nag spam, stats column mismatch, per-call regex/replacer allocs.

- Update README: forex commands, Finance section, 47 plugins.

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

internal/plugin/flip.go

@@ -1,7 +1,6 @@
 package plugin
 
 import (
-	"context"
 	"fmt"
 	"math/rand/v2"
 	"strings"
@@ -143,7 +142,7 @@ func (p *FlipPlugin) handleLoseboard(ctx MessageContext) error {
 	var sb strings.Builder
 	sb.WriteString("🐝 **GogoBee's Trophy Wall**\n\n")
 	for i, uid := range order {
-		name := p.flipDisplayName(id.UserID(uid))
+		name := p.DisplayName(id.UserID(uid))
 		stats := users[uid]
 		var parts []string
 		for game, count := range stats.breakdown {
@@ -163,8 +162,7 @@ func (p *FlipPlugin) handleLoseboard(ctx MessageContext) error {
 // recordBotDefeat increments the bot defeat counter for a user in a specific game.
 // This is a package-level function so all game plugins can call it.
 func recordBotDefeat(userID id.UserID, game string) {
-	d := db.Get()
-	_, _ = d.Exec(
+	db.Exec("flip: record bot defeat",
 		`INSERT INTO bot_defeats (user_id, game, losses)
 		 VALUES (?, ?, 1)
 		 ON CONFLICT(user_id, game) DO UPDATE SET
@@ -173,13 +171,7 @@ func recordBotDefeat(userID id.UserID, game string) {
 	)
 }
 
-func (p *FlipPlugin) flipDisplayName(userID id.UserID) string {
-	resp, err := p.Client.GetDisplayName(context.Background(), userID)
-	if err != nil || resp.DisplayName == "" {
-		return string(userID)
-	}
-	return resp.DisplayName
-}
+
 
 // redirectToGamesRoom returns the room ID for games-restricted redirect.
 func redirectToGamesRoom(sender id.UserID) string {