axon-fmt vs indenter vs powerfmt

Token-level lossless formatter for AXON source. Round-trips comments and layout verbatim via the Fase 14 trivia channel from `axon-frontend`; canonicalises only trailing whitespace per line and the final newline. Mirrors the behaviour of `axon fmt` in axon-lang so the language CLI and the LSP format-on-save produce byte-identical output.

A formatter wrapper that indents the text, designed for error display impls

`powerfmt` is a library that provides utilities for formatting values. This crate makes it significantly easier to support filling to a minimum width with alignment, avoid heap allocation, and avoid repetitive calculations.