Detect and filter retweets

[sujito00]

Problem

parseTweet() doesn't detect retweets (tweets where legacy.retweeted_status_result exists). Retweets are parsed and displayed as regular tweets with no indication.

Proposed solution

1. Add an isRetweet boolean field to the Tweet type
2. Parse legacy.retweeted_status_result to extract the original tweet info
3. Add a retweetOf field with the original author and tweet ID
4. Add --no-retweets flag to CLI commands that fetch timelines

interface Tweet {
  // ... existing fields
  isRetweet: boolean;
  retweetOf?: { authorHandle: string; tweetId: string };
}

Why it matters

When analyzing a user's timeline, retweets can dominate the output. Users need to distinguish original content from amplified content.