Function fetch_news_content 

pub async fn fetch_news_content(
    url: &str,
) -> Result<String, Box<dyn Error + Send + Sync>>

What: Fetch the full article content from an Arch news URL.

Inputs:

• url: The news article URL (e.g., https://archlinux.org/news/...)

Output:

• Ok(String) with the article text content; Err on network/parse failure.

Errors

• Network fetch failures
• HTML parsing failures

Details:

• For AUR package URLs, fetches and renders AUR comments instead.
• For Arch news URLs, checks cache first (15-minute in-memory, 14-day disk TTL).
• Applies rate limiting for archlinux.org URLs to prevent aggressive fetching.
• Fetches the HTML page and extracts content from the article body.
• Strips HTML tags and normalizes whitespace.
• Caches successful fetches in both in-memory and disk caches.