Function fetch_srcinfo 

pub async fn fetch_srcinfo(client: &Client, name: &str) -> Result<String>

What: Fetch .SRCINFO content for an AUR package using async HTTP.

Inputs:

• client: Reqwest HTTP client.
• name: AUR package name.

Output:

• Returns .SRCINFO content as a string, or an error if fetch fails.

Errors

• Returns Err when HTTP request fails (network error or client error)
• Returns Err when HTTP response status is not successful
• Returns Err when response body cannot be read
• Returns Err when response is empty or contains HTML error page
• Returns Err when response does not appear to be valid .SRCINFO format

Details:

• Uses reqwest for async fetching with built-in timeout handling.
• Validates that the response is not empty, not HTML, and contains .SRCINFO format markers.
• Requires the aur feature to be enabled.