feat(admin): category SEO fields, Templates admin, safe project PATCH

- categories/tags admin forms: add meta title/description/keywords, bot-follow,
  sort, is_active (backend already supported these)
- new Templates admin (/admin/templates): container CRUD with description,
  keywords, publishing, premium, primary mode, category/tag assignment, plus
  editable per-variant aspect & resolution
- content-svc: PATCH /v1/projects/{id} partial update so aspect/resolution edits
  never wipe render/colour data (SharedColorsSvg, RenderAepComp, Folder)
- admin resource proxy: add PATCH passthrough

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

services/content/FlatRender.ContentSvc/Controllers/TemplatesController.cs

@@ -60,6 +60,12 @@ public class ProjectsController(TemplateService svc) : ControllerBase
     public async Task<IActionResult> UpdateProject(Guid id, [FromBody] UpdateProjectRequest req) =>
         Ok(await svc.UpdateProjectAsync(id, req));
 
+    // Partial update (aspect / resolution / dimensions / duration) without wiping other fields.
+    [Authorize(Roles = "Admin")]
+    [HttpPatch("{id:guid}")]
+    public async Task<IActionResult> PatchProject(Guid id, [FromBody] PatchProjectRequest req) =>
+        Ok(await svc.PatchProjectAsync(id, req));
+
     [Authorize(Roles = "Admin")]
     [HttpDelete("{id:guid}")]
     public async Task<IActionResult> DeleteProject(Guid id)