fix(site): contain the docs header content to the page width

The .hscli-header override was full-bleed, so on wide viewports the right-group (search/theme/GitHub) floated to the viewport edge — ~120px past where the page content ends. Cap it to --maxw and center, matching the home header. Header background stays full-width.

Author: wavyx

website/src/styles/custom.css

@@ -332,6 +332,11 @@ h1#_top,
    ============================================================ */
 .hscli-header {
   display: flex; align-items: center; gap: 22px; height: 100%;
+  /* Contain the header content like the rest of the page instead of letting
+     it span the full viewport (which floated the actions to the screen edge). */
+  max-width: var(--maxw);
+  margin-inline: auto;
+  padding-inline: 1rem;
 }
 .hscli-header .header-spacer { flex: 1; }
 .hscli-header .header-actions { display: flex; align-items: center; gap: 8px; }