feat(admin): project (template-item) manager + After Effects file upload

The admin could edit a container but not manage its renderable projects or attach
AE files. Now, inside the template editor:
- add a new project/variant under the container (name, WxH, aspect, resolution,
  duration, fps, choose-mode) → POST /v1/projects (maps via container_id)
- upload the After Effects file (.aep/.zip) per project → new PATCH
  /v1/projects/{id}/aep (sets AepFileUrl/Minio/Md5/Size + RenderAepComp), with an
  "AE ✓ / بدون فایل" status badge
- set the render composition name; delete a variant
- ProjectResponse now surfaces aep_file_url / aep_file_size_bytes / render_aep_comp

Additive only — the existing aspect/resolution variant editing is unchanged.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

services/content/FlatRender.ContentSvc/Models/Requests/Requests.cs

@@ -244,6 +244,16 @@ public record UpdateProjectRequest(
 
 // Partial update — only non-null fields are applied, so editing an aspect/resolution
 // never wipes render/colour data that the full UpdateProjectRequest would require.
+public record SetAepRequest(
+    string? AepFileUrl,
+    string? AepMinioBucket,
+    string? AepMinioKey,
+    string? AepFileMd5,
+    long? AepFileSizeBytes,
+    string? RenderAepComp,
+    string? Folder
+);
+
 public record PatchProjectRequest(
     string? Name,
     string? Description,