fix: replace ifconfig.me with icanhazip.com for reliable IP fallback

Previously, the fallback API (ifconfig.me) would return full HTML content instead of plain text IP addresses, causing the 'Before' and 'After' IP display to show HTML pages. Switch to icanhazip.com which consistently returns plain text IPs.

Co-Authored-By: Claude Haiku 4.5 <noreply@anthropic.com>

Author: ashu17706

src/ip.rs

@@ -6,7 +6,7 @@ pub fn get_public_ip() -> Result<String> {
     match get_ip_from_ipify() {
         Ok(ip) => Ok(ip),
         Err(_) => {
-            // Fallback to ifconfig.me
+            // Fallback to icanhazip.com
             get_ip_from_ifconfig()
         }
     }
@@ -29,11 +29,11 @@ fn get_ip_from_ipify() -> Result<String> {
     Ok(ip)
 }
 
-/// Get IP from ifconfig.me as fallback
+/// Get IP from icanhazip.com as fallback
 fn get_ip_from_ifconfig() -> Result<String> {
     let client = reqwest::blocking::Client::new();
     let response = client
-        .get("https://ifconfig.me")
+        .get("https://icanhazip.com")
         .timeout(std::time::Duration::from_secs(5))
         .send()?;