Output Formats

1. flat – Returns a flat array of values (or [key, value] pairs).
2. tree – Returns a nested tree of nodes: { key, value, children }.
3. nestedKeys – Returns nested keys only.
4. simple – Returns direct keys or mapped values of the object.

Additional helper walkers are included for specialized tasks:

• keysOnly – Extract only keys.
• valuesOnly – Extract only values.
• pathsOnly – Extract full paths.
• groupByType – Group keys by value type.
• countValues – Count occurrences of values/arrays.
• filterAndMap – Apply filter and map recursively.