fix(deps): pin @vue/server-renderer to vue + regen lock in linux

Renovate's vue-monorepo group only bumps direct deps. @vue/server-renderer
is pulled transitively via @vue/test-utils and has an exact-pin peer on
vue, so vue minor bumps fail ERESOLVE.

Use npm overrides with \$vue to keep @vue/server-renderer in lockstep
with vue automatically. Lockfile regenerated inside cypress/base:26.0.0
container so the linux-side optional-dep graph (@emnapi/core, @emnapi/runtime)
is materialized correctly — macOS npm 11.6 cross-platform mode does not.

package.json

@@ -63,5 +63,8 @@
   },
   "engines": {
     "node": "24"
+  },
+  "overrides": {
+    "@vue/server-renderer": "$vue"
   }
 }