refactor: config settings shown as badges with pencil-to-edit

Settings (log level, engine level, payload capture, metrics) now
display as color-coded badges by default. Clicking the pencil icon
enters edit mode where badges become dropdowns. Save (checkmark)
persists changes and reverts to badge view; cancel discards changes.

Applied consistently on both the admin App Config page and the
AgentHealth config bar.

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

ui/src/pages/Admin/AppConfigPage.module.css

@@ -16,6 +16,34 @@
   opacity: 1;
 }
 
+.editBtn {
+  background: transparent;
+  border: none;
+  color: var(--text-faint);
+  opacity: 0.75;
+  cursor: pointer;
+  font-size: 13px;
+  padding: 2px 4px;
+  border-radius: var(--radius-sm);
+  line-height: 1;
+  display: inline-flex;
+}
+
+.editBtn:hover {
+  color: var(--text-primary);
+  opacity: 1;
+}
+
+.editBtn:disabled {
+  opacity: 0.3;
+  cursor: not-allowed;
+}
+
+.editActions {
+  display: inline-flex;
+  gap: 2px;
+}
+
 .inlineSelect {
   padding: 3px 8px;
   border: 1px solid var(--border-subtle);