Add filtered navigation to share pages

- Update share API to return websiteId and parameters
- Create ShareNav component that filters nav items based on parameters
- Update SharePage to include navigation sidebar and route to correct page
- Support all website pages: overview, events, sessions, realtime, compare,
  breakdown, goals, funnels, journeys, retention, utm, revenue, attribution

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

src/app/api/share/[slug]/route.ts

@@ -12,7 +12,11 @@ export async function GET(_request: Request, { params }: { params: Promise<{ slu
     return notFound();
   }
 
-  const data = { shareId: share.id };
+  const data = {
+    shareId: share.id,
+    websiteId: share.entityId,
+    parameters: share.parameters,
+  };
   const token = createToken(data, secret());
 
   return json({ ...data, token });