Feat(tools): open the Advanced Tools as pages

Every way into a tool — the homepage cards, the nav dropdown and mobile
sheet, the keyboard shortcuts, ASN Info's profile link, the banners —
navigates to /tools/<slug>; the bottom drawer, its full-screen toggle
and the ?tool= query it was driven by are gone from Advanced.vue. The
pages stay alive (App.vue / ToolPage.vue), so browser back and forward
move between tools and the homepage, each restored as it was left.

Legacy /?tool=<slug> links redirect to the page in a router beforeEach
(utils/legacy-tool-link.js: known slug → its page with the remaining
query, unknown → the homepage). Persona Check drops noStandalone: with
the homepage kept alive its dependency commands stay registered, so the
page dispatches them in place and only a direct visit navigates home
first. The four sign-in tools no longer close a drawer before opening
the usage dialog, which PageHeader's User hosts.

Changelog entries in the six full locales; frontend/AGENTS.md describes
the page model.

Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_013GbLTGMZ45MV78qd2tHoco

index.html

@@ -469,7 +469,8 @@
   </noscript>
 
   <!-- Vue mounts here. `vaul-drawer-wrapper` is the marker vaul-vue uses to scale
-      the page background when a bottom drawer is open (Advanced Tools panel). -->
+      the page background when a bottom drawer is open (the expanded ASN
+      connectivity graph, ip-infos/ASNConnectivity.vue). -->
   <div id="app" vaul-drawer-wrapper></div>
   <script type="module" src="/frontend/main.js"></script>
 </body>