Add action economy split and cross-plugin chat level lookup (Adventure 2.5 steps 1-2)

Action economy: replace single daily action with 1 combat + 3 harvest
actions per day. Holidays grant +1 to each bucket. Rest consumes all
remaining actions. Arena remains outside both buckets.

- Add CombatActionsUsed/HarvestActionsUsed counters to AdventureCharacter
- Add CanDoCombat/CanDoHarvest/AllActionsUsed/HasActedToday helpers
- Update all 14 ActionTakenToday check sites across adventure, scheduler,
  babysit, twinbee, events, and render
- Morning DM shows action budget and grays out exhausted categories
- Activity resolution checks per-bucket availability before proceeding
- Midnight reset zeros both counters
- Post-action nudge shows remaining actions instead of holiday prompt

Cross-plugin lookup: export XPPlugin.GetLevel(), wire into AdventurePlugin
via p.chatLevel(userID) for upcoming chat level perks.

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

internal/db/db.go

@@ -83,6 +83,8 @@ func runMigrations(d *sql.DB) error {
 		`ALTER TABLE adventure_characters ADD COLUMN robbie_visit_count INTEGER NOT NULL DEFAULT 0`,
 		`ALTER TABLE wordle_stats ADD COLUMN total_earned INTEGER NOT NULL DEFAULT 0`,
 		`ALTER TABLE adventure_characters ADD COLUMN last_death_date TEXT NOT NULL DEFAULT ''`,
+		`ALTER TABLE adventure_characters ADD COLUMN combat_actions_used INTEGER NOT NULL DEFAULT 0`,
+		`ALTER TABLE adventure_characters ADD COLUMN harvest_actions_used INTEGER NOT NULL DEFAULT 0`,
 	}
 	for _, stmt := range columnMigrations {
 		if _, err := d.Exec(stmt); err != nil {