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/movies.go

@@ -119,18 +119,26 @@ func (p *MoviesPlugin) Init() error { return nil }
 func (p *MoviesPlugin) OnReaction(_ ReactionContext) error { return nil }
 
 func (p *MoviesPlugin) OnMessage(ctx MessageContext) error {
-	if p.IsCommand(ctx.Body, "movie") {
-		return p.handleMovie(ctx)
-	}
-	if p.IsCommand(ctx.Body, "tv") {
-		return p.handleTV(ctx)
-	}
-	if p.IsCommand(ctx.Body, "upcoming") {
+	var handler func(MessageContext) error
+	switch {
+	case p.IsCommand(ctx.Body, "movie"):
+		handler = p.handleMovie
+	case p.IsCommand(ctx.Body, "tv"):
+		handler = p.handleTV
+	case p.IsCommand(ctx.Body, "upcoming"):
 		args := p.GetArgs(ctx.Body, "upcoming")
 		if strings.ToLower(strings.TrimSpace(args)) == "movies" {
-			return p.handleUpcoming(ctx)
+			handler = p.handleUpcoming
 		}
 	}
+	if handler == nil {
+		return nil
+	}
+	go func() {
+		if err := handler(ctx); err != nil {
+			slog.Error("movies: handler error", "err", err)
+		}
+	}()
 	return nil
 }
 
@@ -221,14 +229,11 @@ func (p *MoviesPlugin) fetchMovieDetail(movieID int) (*tmdbMovieDetail, error) {
 
 	// Update cache
 	data, _ := json.Marshal(detail)
-	_, err = d.Exec(
+	db.Exec("movies: cache write",
 		`INSERT INTO movie_cache (tmdb_id, data, cached_at) VALUES (?, ?, ?)
 		 ON CONFLICT(tmdb_id) DO UPDATE SET data = ?, cached_at = ?`,
 		movieID, string(data), time.Now().Unix(), string(data), time.Now().Unix(),
 	)
-	if err != nil {
-		slog.Error("movies: cache write", "err", err)
-	}
 
 	return &detail, nil
 }