Refactor Gemini protocol implementation and improve server architecture

- Move gemini URL parsing from common/ to gemini/ package
- Add structured status codes in gemini/status_codes.go
- Improve error handling with proper Gemini status codes
- Update configuration field naming (Listen -> ListenAddr)
- Add UTF-8 validation for URLs
- Enhance security with better path validation
- Add CLAUDE.md for development guidance
- Include example content in srv/ directory
- Update build system to use standard shell

main.go

@@ -14,12 +14,16 @@ import (
 	"time"
 
 	"gemserve/config"
+	"gemserve/gemini"
 	"gemserve/server"
 	logging "git.antanst.com/antanst/logging"
 	"git.antanst.com/antanst/uid"
 	"git.antanst.com/antanst/xerrors"
 )
 
+// This channel is for handling fatal errors
+// from anywhere in the app. The consumer
+// should log and panic.
 var fatalErrors chan error
 
 func main() {
@@ -37,7 +41,7 @@ func main() {
 func runApp() error {
 	logging.LogInfo("Starting up. Press Ctrl+C to exit")
 
-	listenHost := config.CONFIG.Listen
+	listenAddr := config.CONFIG.ListenAddr
 
 	signals := make(chan os.Signal, 1)
 	signal.Notify(signals, syscall.SIGINT, syscall.SIGTERM)
@@ -45,7 +49,7 @@ func runApp() error {
 	fatalErrors = make(chan error)
 
 	go func() {
-		err := startServer(listenHost)
+		err := startServer(listenAddr)
 		if err != nil {
 			fatalErrors <- xerrors.NewError(err, 0, "Server startup failed", true)
 		}
@@ -62,7 +66,7 @@ func runApp() error {
 	}
 }
 
-func startServer(listenHost string) (err error) {
+func startServer(listenAddr string) (err error) {
 	cert, err := tls.LoadX509KeyPair("certs/server.crt", "certs/server.key")
 	if err != nil {
 		return xerrors.NewError(fmt.Errorf("failed to load certificate: %w", err), 0, "Certificate loading failed", true)
@@ -73,7 +77,7 @@ func startServer(listenHost string) (err error) {
 		MinVersion:   tls.VersionTLS12,
 	}
 
-	listener, err := tls.Listen("tcp", listenHost, tlsConfig)
+	listener, err := tls.Listen("tcp", listenAddr, tlsConfig)
 	if err != nil {
 		return xerrors.NewError(fmt.Errorf("failed to create listener: %w", err), 0, "Listener creation failed", true)
 	}
@@ -87,7 +91,7 @@ func startServer(listenHost string) (err error) {
 		}
 	}(listener)
 
-	logging.LogInfo("Server listening on %s", listenHost)
+	logging.LogInfo("Server listening on %s", listenAddr)
 
 	for {
 		conn, err := listener.Accept()
@@ -106,7 +110,7 @@ func startServer(listenHost string) (err error) {
 					fatalErrors <- asErr
 					return
 				} else {
-					logging.LogWarn("%s %s Connection failed: %d %s (%v)", connId, remoteAddr, asErr.Code, asErr.UserMsg, err)
+					logging.LogWarn("%s %s Connection failed: %v", connId, remoteAddr, err)
 				}
 			}
 		}()
@@ -157,7 +161,7 @@ func handleConnection(conn *tls.Conn, connId string, remoteAddr string) (err err
 			code = xErr.Code
 			responseMsg = xErr.UserMsg
 		} else {
-			code = 50
+			code = gemini.StatusPermanentFailure
 			responseMsg = "server error"
 		}
 		responseHeader = fmt.Sprintf("%d %s", code, responseMsg)