feat: add network mode with combined HTTP and SSE endpoints

- Add new 'network' transport mode that serves both HTTP and SSE endpoints simultaneously
- HTTP endpoint available on specified port (/mcp)
- SSE endpoint available on port+1 (/sse)
- Maintain backward compatibility with stdio, http, sse modes
- Update documentation and examples for new network mode
- Default to network mode for improved user experience

🤖 Generated with [Claude Code](https://claude.ai/code)

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

cmd/cmd.go

@@ -20,14 +20,14 @@ func init() {
 	flag.StringVar(
 		&flagPkg.Mode,
 		"t",
-		"stdio",
-		"Transport type (stdio, sse or http)",
+		"network",
+		"Transport type (stdio, http, sse, or network). Network mode starts both HTTP and SSE servers",
 	)
 	flag.StringVar(
 		&flagPkg.Mode,
 		"transport",
-		"stdio",
-		"Transport type (stdio, sse or http)",
+		"network",
+		"Transport type (stdio, http, sse, or network). Network mode starts both HTTP and SSE servers",
 	)
 	flag.StringVar(
 		&host,
@@ -39,7 +39,7 @@ func init() {
 		&port,
 		"port",
 		8080,
-		"see or http port",
+		"Network server port (used for both HTTP and SSE endpoints)",
 	)
 	flag.StringVar(
 		&token,