feat: Add subscription management system

- Add subscription fields to organizations (status, plan, trial_ends_at, etc.)
- Add subscription middleware for access control
- Add /auth/me returns subscription info
- Add admin endpoints for subscription management:
  - GET/PUT /admin/organizations/:id/subscription
  - POST /admin/organizations/:id/pause
  - POST /admin/organizations/:id/activate
  - POST /admin/organizations/:id/extend-trial
  - GET /admin/subscriptions (with filters)
- New orgs get 14-day trial automatically

src/db/postgres.ts

@@ -46,7 +46,30 @@ async function runMigrations(client: ReturnType<Pool["connect"]> extends Promise
     `;
     console.log("✅ Migration: logo_url column checked");
   } catch (e) {
-    // Column might already exist, that's fine
+    console.log("ℹ️ Migration note:", e instanceof Error ? e.message : String(e));
+  }
+
+  // Add subscription fields to organizations
+  try {
+    await client.queryObject`
+      ALTER TABLE organizations 
+      ADD COLUMN IF NOT EXISTS subscription_status TEXT DEFAULT 'trial',
+      ADD COLUMN IF NOT EXISTS subscription_plan TEXT DEFAULT 'starter',
+      ADD COLUMN IF NOT EXISTS trial_ends_at TIMESTAMP,
+      ADD COLUMN IF NOT EXISTS subscription_ends_at TIMESTAMP,
+      ADD COLUMN IF NOT EXISTS subscription_paused_at TIMESTAMP,
+      ADD COLUMN IF NOT EXISTS subscription_pause_reason TEXT
+    `;
+    console.log("✅ Migration: subscription columns checked");
+    
+    // Set trial_ends_at for existing orgs without it (14 days from now)
+    await client.queryObject`
+      UPDATE organizations 
+      SET trial_ends_at = NOW() + INTERVAL '14 days'
+      WHERE trial_ends_at IS NULL AND subscription_status = 'trial'
+    `;
+    console.log("✅ Migration: trial dates initialized");
+  } catch (e) {
     console.log("ℹ️ Migration note:", e instanceof Error ? e.message : String(e));
   }
 }