add rate limiting, retry logic, and progress tracking for tweet deletion

[plusz]

• Track deleted tweets in deleted_tweets.txt to support resume on interruption
• Add 20s delay between deletions to stay within 50 requests per 15 minutes limit
• Implement retry logic with exponential backoff for connection errors and timeouts
• Handle 429 rate limit responses with automatic waiting until reset time
• Display rate limit status and progress counter (current/total)
• Add extra delay when rate limit remaining