Fix vertical alignment of .commit-sign-badge children (#36570)

Before: Avatar and lock icon was slightly misaligned vertically and span
was `20px` high:

<img width="271" height="69" alt="Screenshot 2026-02-09 at 14 38 45"
src="https://github.com/user-attachments/assets/e7e7ff6b-3087-4baa-95b5-18dc54c595d7"
/>

After: Fixed alignment and span is `16px`, same as avatar:

<img width="270" height="65" alt="Screenshot 2026-02-09 at 14 39 30"
src="https://github.com/user-attachments/assets/fe31a23e-c6d8-49d3-92a3-237628da1269"
/>

web_src/css/repo/commit-sign.css

@@ -7,6 +7,10 @@
   flex-shrink: 0;
 }
 
+.ui.label.commit-sign-badge > * {
+  display: flex;
+}
+
 .ui.label.commit-id-short {
   font-family: var(--fonts-monospace);
   height: 24px;