chore: relocate backend into apps/api ahead of monorepo merge

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

apps/api/models/advertisements/advertisements.attributes.js

@@ -0,0 +1,62 @@
+// models/advertisements/advertisements.attributes.js
+
+// ─── Exclude sets ─────────────────────────────────────────────────────────────
+
+// Fields hidden from all roles (internal/denormalized details)
+const excludeAttributes = [
+  "image_asset_id",   // internal FK, "image" association exposes the resolved asset instead
+];
+
+// Admins see everything except the base excludes
+const adminExclude = [
+  ...excludeAttributes,
+];
+
+// Regular users also cannot see audit trails, soft-delete info, or click metrics
+const userExclude = [
+  ...excludeAttributes,
+  "click_count",
+  "createdBy",
+  "updatedBy",
+  "deletedBy",
+  "deletedAt",
+];
+
+// ─── JSONB schemas ──────────────────────────────────────────────────────────
+// Describes shape of the `ctas` JSONB column for paginate's coercion/validation step.
+const jsonbSchemas = {
+  ctas: {
+    type: "array",
+    itemShape: {
+      label:   "string",
+      link:    "string",
+      variant: "string", // "default" | "outline"
+    },
+  },
+  badge_labels: {
+    type: "array",
+    itemShape: "string",
+  },
+};
+
+// ─── Computed attributes ──────────────────────────────────────────────────────
+// Add any SQL-computed fields here (e.g. a "is_currently_live" derived flag).
+// Format: { key, label, type, order, literal }
+const computedAttributes = [
+  // Example:
+  // {
+  //   key:     "is_live",
+  //   label:   "Currently Live",
+  //   type:    "boolean",
+  //   order:   99,
+  //   literal: `("Advertisement"."is_active" = true AND "Advertisement"."start_date" <= NOW() AND ("Advertisement"."end_date" IS NULL OR "Advertisement"."end_date" >= NOW()))`,
+  // },
+];
+
+module.exports = {
+  excludeAttributes,
+  adminExclude,
+  userExclude,
+  jsonbSchemas,
+  computedAttributes,
+};