feat: add site-wide glossary with hover tooltips

Every abbreviation and technical term used in the site's copy (RBAC,
NAPALM, config drift, ...) now links to a new /glossary page and shows
a short definition on hover, wherever it appears in body text. Product
and vendor brand names are deliberately excluded — the glossary stays
a dictionary of vocabulary, not a company directory.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

src/pages/Roadmap.tsx

@@ -1,4 +1,5 @@
 import { useLang } from '../context/LangContext'
+import { linkify } from '../lib/glossary'
 
 type Item = { title: string; detail: string; nis2?: boolean }
 type Group = { label: string; items: Item[] }
@@ -193,7 +194,7 @@ export default function Roadmap() {
                         <span className="text-sm font-medium text-slate-200">{item.title}</span>
                         {item.nis2 && <Nis2Badge />}
                       </div>
-                      <p className="text-sm text-slate-500 leading-relaxed">{item.detail}</p>
+                      <p className="text-sm text-slate-500 leading-relaxed">{linkify(item.detail)}</p>
                     </div>
                   </div>
                 ))}