Add WOTD language rotation, fancy word detection, arena improvements, and death consolidation

- Rotate WOTD between Portuguese, French, and English daily with cognate filtering
- Replace LLM-based fancy word detection with DreamDict frequency data (batch API + cache)
- Track fancy word usage per user and add Wordsmith archetype
- Restore full arena combat flavor text and add player miss actions
- Consolidate death logic into Kill() method with 2-hour lockout
- Fix arena death XP grant missing level-up check
- Fix LLM wotd_used classification by injecting actual WOTD into prompt

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

internal/db/db.go

@@ -73,6 +73,7 @@ func runMigrations(d *sql.DB) error {
 		`ALTER TABLE adventure_characters ADD COLUMN masterwork_drops_received INTEGER NOT NULL DEFAULT 0`,
 		`ALTER TABLE adventure_inventory ADD COLUMN slot TEXT NOT NULL DEFAULT ''`,
 		`ALTER TABLE adventure_inventory ADD COLUMN skill_source TEXT NOT NULL DEFAULT ''`,
+		`ALTER TABLE user_stats ADD COLUMN fancy_words INTEGER NOT NULL DEFAULT 0`,
 	}
 	for _, stmt := range columnMigrations {
 		if _, err := d.Exec(stmt); err != nil {
@@ -243,6 +244,7 @@ CREATE TABLE IF NOT EXISTS user_stats (
 	total_emojis INTEGER DEFAULT 0,
 	night_messages INTEGER DEFAULT 0,
 	morning_messages INTEGER DEFAULT 0,
+	fancy_words INTEGER DEFAULT 0,
 	updated_at INTEGER DEFAULT (unixepoch())
 );