Fix template type error on SSO clients page

{{if not .Clients}} fails when .Clients is a non-nil empty slice
because Go templates expect a bool operand for 'not'. Use
{{if eq (len .Clients) 0}} instead.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

internal/ui/handlers_sso_clients.go

@@ -12,12 +12,14 @@ import (
 func (u *UIServer) handleSSOClientsPage(w http.ResponseWriter, r *http.Request) {
 	csrfToken, err := u.setCSRFCookies(w)
 	if err != nil {
+		u.logger.Error("sso-clients: set CSRF cookies", "error", err)
 		http.Error(w, "internal error", http.StatusInternalServerError)
 		return
 	}
 
 	clients, err := u.db.ListSSOClients()
 	if err != nil {
+		u.logger.Error("sso-clients: list clients", "error", err)
 		u.renderError(w, r, http.StatusInternalServerError, "failed to load SSO clients")
 		return
 	}

web/templates/sso_clients.html

@@ -1,3 +1,4 @@
+{{define "sso_clients"}}{{template "base" .}}{{end}}
 {{define "title"}} - SSO Clients{{end}}
 {{define "content"}}
 <div class="page-header d-flex justify-between align-center">
@@ -48,6 +49,6 @@
       {{end}}
     </tbody>
   </table>
-  {{if not .Clients}}<p class="text-muted" style="text-align:center;padding:2rem">No SSO clients registered.</p>{{end}}
+  {{if eq (len .Clients) 0}}<p class="text-muted" style="text-align:center;padding:2rem">No SSO clients registered.</p>{{end}}
 </div>
 {{end}}