Implement BACKLOG.md items: config-only, request limits, URL validation

- Remove CLI options except --config and --test-processing-delay
- Enforce 1026 byte request limit per Gemini spec (1024 + 2 for CRLF)
- Add comprehensive URL parsing with host and port validation
- Reject malformed URIs and wrong ports with 59 Bad Request
- Update tests for new URL parsing signature
- Fix clippy warning in port parsing

src/request.rs

@@ -6,14 +6,34 @@ pub enum PathResolutionError {
     NotFound,
 }
 
-pub fn parse_gemini_url(request: &str, expected_host: &str) -> Result<String, ()> {
+pub fn parse_gemini_url(request: &str, expected_host: &str, expected_port: u16) -> Result<String, ()> {
     if let Some(url) = request.strip_prefix("gemini://") {
-        let host_end = url.find('/').unwrap_or(url.len());
-        let host = &url[..host_end];
+        let host_port_end = url.find('/').unwrap_or(url.len());
+        let host_port = &url[..host_port_end];
+        
+        // Parse host and port
+        let (host, port_str) = if let Some(colon_pos) = host_port.find(':') {
+            let host = &host_port[..colon_pos];
+            let port_str = &host_port[colon_pos + 1..];
+            (host, Some(port_str))
+        } else {
+            (host_port, None)
+        };
+        
+        // Validate host
         if host != expected_host {
             return Err(());  // Hostname mismatch
         }
-        let path = if host_end < url.len() { &url[host_end..] } else { "/" };
+        
+        // Validate port
+        let port = port_str
+            .and_then(|p| p.parse::<u16>().ok())
+            .unwrap_or(1965);
+        if port != expected_port {
+            return Err(());  // Port mismatch
+        }
+        
+        let path = if host_port_end < url.len() { &url[host_port_end..] } else { "/" };
         Ok(path.trim().to_string())
     } else {
         Err(())
@@ -69,18 +89,18 @@ mod tests {
 
     #[test]
     fn test_parse_gemini_url_valid() {
-        assert_eq!(parse_gemini_url("gemini://gemini.jeena.net/", "gemini.jeena.net"), Ok("/".to_string()));
-        assert_eq!(parse_gemini_url("gemini://gemini.jeena.net/posts/test", "gemini.jeena.net"), Ok("/posts/test".to_string()));
+        assert_eq!(parse_gemini_url("gemini://gemini.jeena.net/", "gemini.jeena.net", 1965), Ok("/".to_string()));
+        assert_eq!(parse_gemini_url("gemini://gemini.jeena.net/posts/test", "gemini.jeena.net", 1965), Ok("/posts/test".to_string()));
     }
 
     #[test]
     fn test_parse_gemini_url_invalid_host() {
-        assert!(parse_gemini_url("gemini://foo.com/", "gemini.jeena.net").is_err());
+        assert!(parse_gemini_url("gemini://foo.com/", "gemini.jeena.net", 1965).is_err());
     }
 
     #[test]
     fn test_parse_gemini_url_no_prefix() {
-        assert!(parse_gemini_url("http://gemini.jeena.net/", "gemini.jeena.net").is_err());
+        assert!(parse_gemini_url("http://gemini.jeena.net/", "gemini.jeena.net", 1965).is_err());
     }
 
     #[test]