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/plugin/xp.go

@@ -106,6 +106,16 @@ func (p *XPPlugin) OnMessage(ctx MessageContext) error {
 }
 
 // GrantXP awards XP to a user from an external plugin and returns (newXP, leveledUp, newLevel).
+// GetLevel returns the chat level for the given user, or 0 if unknown.
+func (p *XPPlugin) GetLevel(userID id.UserID) int {
+	d := db.Get()
+	var level int
+	if err := d.QueryRow(`SELECT level FROM users WHERE user_id = ?`, string(userID)).Scan(&level); err != nil {
+		return 0
+	}
+	return level
+}
+
 func (p *XPPlugin) GrantXP(userID id.UserID, amount int, reason string) (int, bool, int) {
 	return p.grantXPInternal(userID, amount, reason)
 }