Migrate the formatter onto lwpt format

[frostney]

Summary

Adopt lwpt format for source formatting.

Why

The lwpt formatter was originally ported from this project's format.pas, so migrating onto lwpt format removes the in-repo formatter while keeping behaviour.

Current behavior

Formatting runs via the in-repo format.pas.

Expected behavior

• lwpt format / lwpt format --check replaces format.pas at behavioural parity.

Scope notes

• Part of the lwpt migration (parent Migrate toolchain to lwpt #826).