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/holdem_game.go

@@ -62,6 +62,7 @@ type HoldemPlayer struct {
 	Bet          int64 // committed this street
 	TotalBet     int64 // committed this hand
 	State        PlayerState
+	HasActed     bool // whether the player has voluntarily acted this street
 	TipsEnabled  bool
 	SittingOut   bool
 	WantsLeave   bool
@@ -90,8 +91,10 @@ type HoldemGame struct {
 	HandInProgress    bool
 	StreetHistory     string // action chars for current street (f/c/r/R/a) for CFR policy lookup
 
-	actionTimer  *time.Timer
-	warningTimer *time.Timer
+	actionTimer      *time.Timer
+	warningTimer     *time.Timer
+	idleTimer        *time.Timer
+	idleWarningTimer *time.Timer
 }
 
 // newShuffledDeck creates a shuffled 52-card deck.
@@ -208,6 +211,7 @@ func (g *HoldemGame) playerIdx(uid id.UserID) int {
 func (g *HoldemGame) resetStreetBets() {
 	for _, p := range g.Players {
 		p.Bet = 0
+		p.HasActed = false
 	}
 	g.CurrentBet = 0
 	g.MinRaise = g.BigBlind