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/healthcheck/checker.go

@@ -439,7 +439,7 @@ func (c *Checker) checkDataTransfer(port int) error {
 	if err != nil {
 		return err
 	}
-	defer conn.Close()
+	defer func() { _ = conn.Close() }()
 
 	// Set a short read deadline to detect hung connections
 	// We don't expect to receive data, but we want to verify the connection isn't hung