refactor(entries): drop the cyan secret marker on the reveal eye

The eye only renders on a secret field, so its presence already carries the state.

js/app.js

@@ -4277,11 +4277,10 @@ function buildCustomFieldRow(field, idx, rerender) {
     });
 
     // The secret flag no longer has a button of its own: two adjacent toggles
-    // that both masked the value read as duplicates. The eye alone carries the
-    // state (cyan ring = stored as secret) and flipping it lives in the row
-    // menu, one deliberate step away from the everyday reveal.
+    // that both masked the value read as duplicates. The eye is shown only on a
+    // secret field, so its presence IS the indicator, and flipping the flag
+    // lives in the row menu, one deliberate step away from the everyday reveal.
     function applySecretState() {
-        eye.classList.toggle('is-secret', !!field.is_secret);
         eye.style.visibility =
             (!field.is_secret || (valueInput.tagName !== 'INPUT' && !field.multiline))
                 ? 'hidden' : '';