Fix WOTD translation requirements, LLM sentiment accuracy, arena death timer, and fancy word detection

WOTD: Require both English and French translations, validate before
display, fall back to English word if pt-PT search exhausts 100 attempts.

LLM passive: Inject actual WOTD into classification prompt instead of
letting LLM guess at "unusual words". Add DreamDict-based fancy word
detection using frequency data — react with 🎓 for rare vocabulary.

Arena: Reduce death lockout from next-midnight-UTC to 2 hours.

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

main.go

@@ -155,7 +155,7 @@ func main() {
 	registry.Register(minifluxPlugin)
 
 	// LLM-powered (passive)
-	registry.Register(plugin.NewLLMPassivePlugin(client, xpPlugin))
+	registry.Register(plugin.NewLLMPassivePlugin(client, xpPlugin, dictClient))
 
 	// Scheduled
 	wotdPlugin := plugin.NewWOTDPlugin(client, dictClient)