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/adventure_flavor_treasure.go

@@ -377,6 +377,7 @@ var SummaryMiningSuccess = []string{
 	"Mining run at {location}: {ore} recovered, €{value}, no cave-ins.",
 	"Came back from {location} with {ore} and €{value} and a worse {tool}.",
 	"{ore} from {location}. €{value}. The back is filing a complaint.",
+	"You went mining. You tripped. You fell into the wall. You're out cold. But a rock broke free. You may have lost 8 hours. But hell, you gained {ore}. €{value}.",
 }
 
 var SummaryMiningDeath = []string{
@@ -400,6 +401,14 @@ var SummaryForagingSuccess = []string{
 	"Returned from {location} with {item} worth €{value} and zero injuries. Good day.",
 	"Clean haul from {location}. {item}, €{value}. The forest cooperated.",
 	"{item} from {location}. €{value}. One bear made eye contact. Moved on.",
+	"You went foraging. You foraged. Yep. Stuff found. Good job. What was it? Who cares? It's foraging. Does it really matter? Okay. Fine. It was {item}. €{value}.",
+}
+
+var SummaryForagingEmpty = []string{
+	"Wandered through {location}. Found nothing. Not even hornets.",
+	"{location}: searched every bush. Came home empty-handed.",
+	"Nothing from {location}. The forest was uncooperative today.",
+	"Went foraging in {location}. The forest kept its things.",
 }
 
 var SummaryForagingDeath = []string{