fix(cmd): handle errors and improve output formatting

* update error handling in various commands to use blank identifier
* enhance output formatting for better readability
* add golangci-lint to Makefile for linting checks

cmd/pgtidy/lsp.go

@@ -12,7 +12,7 @@ import (
 func cmdLsp(args []string, stdin io.Reader, stdout, stderr io.Writer) int {
 	for _, a := range args {
 		if a == "-h" || a == "--help" {
-			fmt.Fprintln(stdout, "pgtidy lsp — start the Language Server Protocol server (stdio transport)")
+			_, _ = fmt.Fprintln(stdout, "pgtidy lsp — start the Language Server Protocol server (stdio transport)")
 			return 0
 		}
 	}
@@ -21,7 +21,7 @@ func cmdLsp(args []string, stdin io.Reader, stdout, stderr io.Writer) int {
 		wd = "."
 	}
 	if err := lsp.Serve(context.Background(), stdin, stdout, wd); err != nil {
-		fmt.Fprintf(stderr, "pgtidy lsp: %v\n", err)
+		_, _ = fmt.Fprintf(stderr, "pgtidy lsp: %v\n", err)
 		return 1
 	}
 	return 0