css: fix nav active state, deduplicate .site-nav__right, add font-display, clean up search pagination

- common.css: add font-display: swap to Combinedd.otf @font-face (eliminates FOIT)
- common.css: remove duplicate .site-nav__right block (identical to .site-nav__link);
  update nav.php to use .site-nav__link on the À Propos link
- common.css: add .site-nav__link--active rule (opacity:1 + white underline); the class
  was already applied in nav.php but had no CSS definition, making it invisible
- search.php: replace fully inline-styled pagination with .pagination-wrap / .pagination-btn
  / .pagination-info classes; add aria-disabled + tabindex=-1 on disabled links;
  add aria-label on prev/next links
- search.css: add pagination rule block to match, keeping styles co-located with the page

public/assets/search.css

@@ -269,6 +269,47 @@ html, body {
   cursor: pointer;
 }
 
+/* Search results pagination — reuses same token names as main.css */
+.pagination-wrap {
+  display: flex;
+  justify-content: center;
+  align-items: center;
+  gap: 0.5rem;
+  padding: 1.5rem 0;
+}
+
+.pagination-btn {
+  display: inline-flex;
+  align-items: center;
+  justify-content: center;
+  min-width: 2rem;
+  height: 2rem;
+  padding: 0 0.5rem;
+  border: 1px solid var(--border-color);
+  border-radius: 3px;
+  color: var(--black);
+  font-size: 0.9rem;
+  text-decoration: none;
+  transition: all 0.15s;
+}
+
+.pagination-btn:hover:not(.disabled) {
+  border-color: var(--purple);
+  color: var(--purple);
+}
+
+.pagination-btn.disabled {
+  opacity: 0.3;
+  cursor: not-allowed;
+  pointer-events: none;
+}
+
+.pagination-info {
+  font-size: 0.9rem;
+  color: var(--text-muted);
+  padding: 0 0.5rem;
+}
+
 .search-empty {
   padding: 3rem 1.5rem;
   color: var(--text-muted);