Fix admin nav selection: use !important to override text-black

The direct bg-stone-500 text-white classes were losing to text-black
in Tailwind specificity. Use !bg-stone-500 !text-white to ensure
selected admin nav items display correctly.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

blog/sexp/sexp_components.py

@@ -120,6 +120,10 @@ def _post_admin_nav_html(ctx: dict, *, selected: str = "") -> str:
     styles = ctx.get("styles") or {}
     nav_btn = styles.get("nav_button", "") if isinstance(styles, dict) else getattr(styles, "nav_button", "")
 
+    # Base and selected class for nav items
+    base_cls = "justify-center cursor-pointer flex flex-row items-center gap-2 rounded bg-stone-200 text-black p-3"
+    selected_cls = "justify-center cursor-pointer flex flex-row items-center gap-2 rounded !bg-stone-500 !text-white p-3"
+
     parts = []
 
     # External links to events / market services
@@ -134,9 +138,10 @@ def _post_admin_nav_html(ctx: dict, *, selected: str = "") -> str:
             if not callable(url_fn):
                 continue
             href = url_fn(path)
+            cls = selected_cls if label == selected else (nav_btn or base_cls)
             parts.append(render("blog-admin-nav-item",
-                href=href, nav_btn_class=nav_btn, label=label,
-                is_selected=(label == selected), select_colours=select_colours,
+                href=href, nav_btn_class=cls, label=label,
+                select_colours=select_colours,
             ))
 
     # HTMX links
@@ -147,9 +152,11 @@ def _post_admin_nav_html(ctx: dict, *, selected: str = "") -> str:
         ("blog.post.admin.settings", "settings"),
     ]:
         href = qurl(endpoint, slug=slug)
+        is_sel = label == selected
         parts.append(render("nav-link",
             href=href, label=label, select_colours=select_colours,
-            is_selected=(label == selected),
+            is_selected=is_sel,
+            aclass=(selected_cls + " " + select_colours) if is_sel else None,
         ))
 
     return "".join(parts)