feat: Add vertical remote plugin collection support (#23584)

- Adds an explicit vertical marketplace kind for plugin/list that
fail-open fetches collection=vertical only when full remote plugins are
disabled.

- Renames the global remote marketplace/cache identity to
openai-curated-remote and materializes remote installs with backend
release versions and app manifests.

codex-rs/app-server-protocol/schema/json/ClientRequest.json

@@ -1632,6 +1632,7 @@
     "PluginListMarketplaceKind": {
       "enum": [
         "local",
+        "vertical",
         "workspace-directory",
         "shared-with-me"
       ],