feat: link RBAC editor from dossier privacy section

Updated "Edit" button in dossier Privacy section to open new RBAC editor
instead of old access editor. Users can now access granular per-category
permissions directly from the dossier page.

Location: Privacy section → Edit button next to each person with access

Route changed: /dossier/{id}/access/{grantee_id} → /dossier/{id}/rbac/{grantee_id}

Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>

portal/templates/dossier.tmpl

@@ -40,7 +40,7 @@
         </div>
         {{if and $.CanManageAccess (not .IsSelf)}}
         <div style="display: flex; gap: 8px;">
-          <a href="/dossier/{{$.TargetDossier.DossierID}}/access/{{.DossierID}}" class="btn btn-secondary btn-small">Edit</a>
+          <a href="/dossier/{{$.TargetDossier.DossierID}}/rbac/{{.DossierID}}" class="btn btn-secondary btn-small">Edit</a>
           <form action="/dossier/{{$.TargetDossier.DossierID}}/revoke" method="POST" style="display:inline;">
             <input type="hidden" name="accessor_id" value="{{.DossierID}}">
             <button type="submit" class="btn btn-danger btn-small" onclick="return confirm('Remove access for {{.Name}} to {{$.TargetDossier.Name}}?')">{{$.T.remove}}</button>