download-spec contextual menu option serves stale/cached spec content, and mislabels JSON as .yaml

[NizarBerjawi]

Summary:

The download-spec contextual menu option has two bugs:

1. Stale content: The downloaded zip file contains a stale version of the OpenAPI spec and the correct version. The stale spec does not exist anywhere in the source repository. The live docs pages themselves show the current spec correctly; only the download action serves outdated data, suggesting the download path is hitting a cache that isn't invalidated on redeploy.
2. Wrong file format: the downloaded file keeps the source .yaml filename, but its contents are JSON, not YAML.

Config used:

{
  "navigation": {
    "tabs": [
      {
        "tab": "API reference",
        "icon": "terminal",
        "pages": [
          {
            "group": "Endpoints",
            "expanded": false,
            "openapi": "api-reference/openapi.yaml"
          }
        ]
      }
    ]
  },
  "contextual": {
    "options": [
      "copy",
      "download-spec",
      "mcp",
      "add-mcp",
      "chatgpt",
      "claude",
      "cursor",
      "vscode"
    ]
  }
}

Steps to reproduce:

1. Point docs.json's openapi navigation entry at a .yaml file.
2. Add download-spec to contextual.options.
3. Open any API reference page on the deployed site, click the contextual menu → "Download API spec".

Expected:

• Downloaded content matches the currently deployed spec.
• File format/extension are consistent (real YAML if named .yaml, or .json if the content is JSON).

Actual:

• Downloaded file contains endpoints/content that no longer exist in the repo or the live rendered pages — looks like a stale cache.
• File is named openapi-v2_3.yaml but contains JSON.

Impact: Minor but confusing — anyone opening the file in an editor expecting YAML gets JSON. Not documented either way on the contextual menu docs page.