feat(read-post): request note_tweet and article fields for long-form …

[kenkenchu]

Summary

• Adds note_tweet and article to the tweet.fields parameter in ReadPost
• The X API will now return long-form article and Notes content when present on a post
• No change to the public function signature — callers receive the additional fields as part of the
  existing raw JSON response

Test plan

• Run xurl read <post-id> on a post that is an X Note — verify note_tweet field appears in
  the response
• Run xurl read <post-id> on a post that links to a long-form article — verify article field
  appears in the response
• Run xurl read <post-id> on a regular post — verify existing behaviour is unchanged

[CLAassistant]

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