Add initial server health check and update Harbor versions

src/web/styles.css

@@ -2728,13 +2728,26 @@ p {
   margin-bottom: 14px;
 }
 
+.client-server-toolbar {
+  display: grid;
+  grid-template-columns: 1fr auto 1fr;
+  align-items: center;
+  margin-bottom: 8px;
+}
+
+.client-server-toolbar.is-single {
+  display: flex;
+  justify-content: center;
+}
+
 .client-server-mode-toggle {
   min-height: 32px;
   display: flex;
   align-items: center;
   justify-content: center;
   gap: 7px;
-  margin: 0 auto 8px;
+  grid-column: 2;
+  margin: 0;
   padding: 5px 8px;
   border: 0;
   background: transparent;
@@ -2744,6 +2757,34 @@ p {
   transition: color 220ms ease, text-shadow 320ms ease;
 }
 
+.client-server-check {
+  grid-column: 3;
+  justify-self: start;
+  width: 88px;
+  min-height: 32px;
+  padding: 5px 7px;
+  border: 0;
+  background: transparent;
+  color: var(--client-muted);
+  font: 700 8px/1.2 'JetBrains Mono', 'SF Mono', ui-monospace, Menlo, monospace;
+  cursor: pointer;
+}
+
+.client-server-check:hover:not(:disabled),
+.client-server-check:focus-visible {
+  color: var(--client-accent);
+}
+
+.client-server-check:focus-visible {
+  outline: 2px solid var(--client-accent);
+  outline-offset: 1px;
+}
+
+.client-server-check:disabled {
+  cursor: default;
+  opacity: 0.55;
+}
+
 .client-server-mode-toggle:hover,
 .client-server-mode-toggle.is-open {
   color: var(--client-accent);