Fix dashboard SQL: use tier_level and mrr_value columns

The subscriptions table uses:
- tier_level (integer) not tier_id
- mrr_value (pre-calculated) not joined to subscription_tiers
- is_lifetime (boolean) not status='lifetime'

Chronicler #69

services/arbiter-3.0/src/routes/admin/index.js

@@ -34,12 +34,8 @@ router.get('/dashboard', async (req, res) => {
         // Fetch subscriber stats from database
         const { rows: subStats } = await db.query(`
             SELECT 
-                COUNT(*) FILTER (WHERE status IN ('active', 'grace_period', 'lifetime')) as active_count,
-                COALESCE(SUM(CASE 
-                    WHEN status = 'active' AND tier_id IS NOT NULL THEN 
-                        (SELECT price FROM subscription_tiers WHERE id = tier_id)
-                    ELSE 0 
-                END), 0) as mrr
+                COUNT(*) FILTER (WHERE status IN ('active', 'grace_period') OR is_lifetime = true) as active_count,
+                COALESCE(SUM(mrr_value) FILTER (WHERE status = 'active'), 0) as mrr
             FROM subscriptions
         `);