feat(content+admin): content ranking + statistics dashboard

- content-svc: template list gains popularity/rating sort modes (use_count_desc,
  popular, rating_desc); new PATCH /v1/templates/{id}/sort to set manual sort
  weight (feature/pin) without a full edit
- admin /admin/ranking: templates ordered by popularity with views/uses/rating
  and inline manual-sort editor
- admin /admin/stats: overview dashboard (users, revenue, paying customers,
  conversion, templates/categories/campaigns/blogs counts) aggregated from
  existing identity + content endpoints
- nav: Dashboard + Ranking links

Completes the epic: SMS/Email/Templates → Marketing → CRM → Ranking + Stats.

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

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

@@ -40,8 +40,19 @@ public class TemplatesController(TemplateService svc) : ControllerBase
         await svc.DeleteContainerAsync(id);
         return NoContent();
     }
+
+    // ── Ranking: set manual sort weight (feature / pin) ─────────────────────────
+    [Authorize(Roles = "Admin")]
+    [HttpPatch("{id:guid}/sort")]
+    public async Task<IActionResult> SetSort(Guid id, [FromBody] SetSortRequest req)
+    {
+        await svc.SetContainerSortAsync(id, req.Sort);
+        return Ok(new { ok = true });
+    }
 }
 
+public record SetSortRequest(int Sort);
+
 [ApiController]
 [Route("v1/projects")]
 public class ProjectsController(TemplateService svc) : ControllerBase