chore: add golangci-lint v2 config and fix linter warnings (#46)

- [x] Add golangci-lint v2 configuration with formatters section
- [x] Reorganize linters-settings under linters section
- [x] Replace if-else chains with switch statements for clarity
- [x] Wrap all ignored error returns with `_ = ` pattern
- [x] Add OSC 8 hyperlink helper function for clickable ports
- [x] Add blank line in table styling function
- [x] Remove unnecessary type assertion in test

internal/benchmark/runner.go

@@ -201,7 +201,7 @@ func (r *Runner) makeRequest(ctx context.Context, cfg Config) (statusCode int, b
 	if err != nil {
 		return 0, 0, bytesWritten, err
 	}
-	defer resp.Body.Close()
+	defer func() { _ = resp.Body.Close() }()
 
 	// Read response body to measure bytes
 	respBody, err := io.ReadAll(resp.Body)