added and fix some of things

Signed-off-by: Kenneth Obsequio <k80308392@gmail.com>

controllers/admin/units.controller.js

@@ -110,6 +110,27 @@ const UNIT_LIST_COMPUTED = [
       END
     )`,
   },
+  {
+    // Not its own column — consumed by the frontend's Subscription cell so a
+    // unit gated only through an affiliated course (own `subscription` is
+    // NULL) still shows a tier instead of "-". Distinct tiers across every
+    // affiliated course, comma-joined (a unit can sit in several courses at
+    // different tiers).
+    key: "course_subscription",
+    label: "Course Subscription",
+    type: "text",
+    hidden: true,
+    filterable: false,
+    literal: `(
+      SELECT STRING_AGG(sub.subscription, ', ')
+      FROM (
+        SELECT DISTINCT c.subscription
+        FROM course_units cu
+        JOIN courses c ON c.course_id = cu.course_id AND c."deletedAt" IS NULL
+        WHERE cu.unit_id = "Unit"."unit_id"
+      ) sub
+    )`,
+  },
 ];
 
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