webui: render NTP empty state gracefully when not configured

The NTP page showed a red "Failed to fetch NTP data" banner whenever
/data/ietf-ntp:ntp returned 404 — which is the normal RESTCONF response
when NTP isn't configured at all. Treat 404 as the not-configured case
and render the empty-state card with a Configure → link, mirroring the
DHCP status page.

Signed-off-by: Joachim Wiberg <troglobit@gmail.com>

src/webui/internal/handlers/ntp.go

@@ -86,8 +86,12 @@ func (h *NTPHandler) Overview(w http.ResponseWriter, r *http.Request) {
 		} `json:"ietf-ntp:ntp"`
 	}
 	if err := h.RC.Get(ctx, "/data/ietf-ntp:ntp", &raw); err != nil {
-		log.Printf("restconf ntp: %v", err)
-		data.Error = "Failed to fetch NTP data"
+		// 404 = NTP container absent (not configured). Render the empty-state
+		// section instead of a red error banner.
+		if !restconf.IsNotFound(err) {
+			log.Printf("restconf ntp: %v", err)
+			data.Error = "Failed to fetch NTP data"
+		}
 	} else {
 		ss := raw.NTP.ClockState.SystemStatus
 		synced := strings.Contains(ss.ClockState, "synchronized") &&

src/webui/templates/pages/ntp.html

@@ -32,8 +32,8 @@
     {{end}}
   </table>
 
-  {{if .NTP.Associations}}
   <h3 class="section-subtitle">Associations</h3>
+  {{if .NTP.Associations}}
   <div class="data-table-wrap">
     <table class="data-table">
       <thead>
@@ -63,12 +63,19 @@
     </table>
   </div>
   {{else}}
-  <p class="text-muted">No associations.</p>
+  <p class="empty-message">No upstream associations to display.</p>
   {{end}}
 </section>
 {{else if not .Error}}
 <section class="info-card">
-  <p class="text-muted">NTP data not available.</p>
+  <div class="card-header">NTP
+    <a href="/configure/tree?path=/ietf-system:system/ntp"
+       hx-get="/configure/tree?path=/ietf-system:system/ntp"
+       hx-target="#content"
+       hx-push-url="true"
+       class="btn btn-sm btn-outline card-header-action">Configure &rarr;</a>
+  </div>
+  <p class="empty-message">NTP is not configured.</p>
 </section>
 {{end}}
 {{end}}