refactor(media): use asset-centric storage key layout

apps/admin/src/lib/media/storage-key.test.ts

@@ -0,0 +1,19 @@
+import { describe, expect, it } from "vitest"
+
+import { buildMediaStorageKey } from "@/lib/media/storage-key"
+
+describe("buildMediaStorageKey", () => {
+  it("builds asset-centric key with fileRole and variant", () => {
+    const key = buildMediaStorageKey({
+      tenantId: "default",
+      assetId: "550e8400-e29b-41d4-a716-446655440000",
+      fileRole: "original",
+      variant: "thumb",
+      fileName: "My File.PNG",
+    })
+
+    expect(key).toBe(
+      "tenant/default/asset/550e8400-e29b-41d4-a716-446655440000/original/550e8400-e29b-41d4-a716-446655440000__thumb.png",
+    )
+  })
+})