refactor: remove SSE transport support from code and documentation (#97)

- Remove support and documentation for sse mode across all language README files
- Update CLI flags and help text to exclude references to sse mode
- Remove SSE server initialization in operation logic
- Adjust error messages to only mention stdio and http transport types
- Update logging setup to remove sse mode conditional logging

See the latest documentation: https://modelcontextprotocol.io/specification/2025-06-18/basic/transports

Signed-off-by: appleboy <appleboy.tw@gmail.com>

Reviewed-on: https://gitea.com/gitea/gitea-mcp/pulls/97
Co-authored-by: appleboy <appleboy.tw@gmail.com>
Co-committed-by: appleboy <appleboy.tw@gmail.com>

cmd/cmd.go

@@ -21,13 +21,13 @@ func init() {
 		&flagPkg.Mode,
 		"t",
 		"stdio",
-		"Transport type (stdio, sse or http)",
+		"Transport type (stdio or http)",
 	)
 	flag.StringVar(
 		&flagPkg.Mode,
 		"transport",
 		"stdio",
-		"Transport type (stdio, sse or http)",
+		"Transport type (stdio or http)",
 	)
 	flag.StringVar(
 		&host,
@@ -39,7 +39,7 @@ func init() {
 		&port,
 		"port",
 		8080,
-		"see or http port",
+		"http port",
 	)
 	flag.StringVar(
 		&token,