feat(web): vercel deployment and vds compose/systemd setup

Add Vercel config with React Router preset, vercel-build script and
/api/auth rewrite to the Convex site. Add VDS staging compose for the
Rivet engine and runner plus systemd units, deployment plan, and
Docker/Vercel ignore rules. Lockfile covers both the web and agents
dependency additions.

packages/backend/convex/gitConnectionData.ts

@@ -145,6 +145,7 @@ export const list = query({
     return connections.map((connection) => ({
       connectedAt: connection.connectedAt,
       credentialKind: connection.credentialKind,
+      grantedScopesJson: connection.grantedScopesJson,
       id: String(connection._id),
       lastVerifiedAt: connection.lastVerifiedAt,
       provider: connection.provider,