Externalize configuration and improve Docker compatibility

- Add STORAGE_DIR and PORT environment variables
- Update tests to use 0.0.0.0 instead of 127.0.0.1 for Docker compatibility
- Update documentation and changelog

src/main.rs

@@ -21,7 +21,7 @@ async fn main() -> tide::Result<()> {
         .ok()
         .and_then(|p| p.parse::<u16>().ok())
         .unwrap_or(DEFAULT_PORT);
-    
+
     // Parse command line arguments
     let args: Vec<String> = env::args().collect();
     let no_ttl_permanent = args.iter().any(|arg| arg == "--permanent");