Enhance air format (#86)

* Add `Parse<RRoot>` utility struct

* Style changes in latest version

* Add multi-file and directory support, add `--check`

* Wrap `ParseDiagnostic` in our `ParseError`

* Clean up a bit with thiserror!

* Add `relativize_path()`

* Add a comment about tracing

* Remove `air_workspace` for now for simplicity

LSP needs `format_node()` since it holds onto the AST, so this isn't as useful yet over there

* Add `is_changed()` for ergonomics

* Remove outdated comment

* Use `u8::MAX` as our catch all error code

For the "something has gone wrong" unexpected error case

* Various tweaks from code review with @lionel-

* Add a TODO to use user supplied line endings in the LSP

* Add a TODO about not normalizing line endings in the cli

* air_fs -> fs

* Ah clippy

Cargo.toml

@@ -27,6 +27,7 @@ air_r_formatter = { path = "./crates/air_r_formatter" }
 air_r_parser = { path = "./crates/air_r_parser" }
 air_r_syntax = { path = "./crates/air_r_syntax" }
 biome_ungrammar = { path = "./crates/biome_ungrammar" }
+fs = { path = "./crates/fs" }
 line_ending = { path = "./crates/line_ending" }
 lsp = { path = "./crates/lsp" }
 lsp_test = { path = "./crates/lsp_test" }
@@ -50,15 +51,18 @@ dissimilar = "1.0.9"
 futures = "0.3.31"
 futures-util = "0.3.31"
 httparse = "1.9.5"
+ignore = "0.4.23"
 insta = "1.40.0"
 itertools = "0.13.0"
 line-index = "0.1.2"
 log = "0.4.22"
 memchr = "2.7.4"
+path-absolutize = "3.1.1"
 proc-macro2 = "1.0.86"
 serde = { version = "1.0.215", features = ["derive"] }
 serde_json = "1.0.132"
 struct-field-names-as-array = "0.3.0"
+thiserror = "2.0.5"
 tokio = { version = "1.41.1" }
 tokio-util = "0.7.12"
 # For https://github.com/ebkalderon/tower-lsp/pull/428