chore(deps): bump acadrust — keep \N column breaks distinct

The MTEXT parser turned `\N` into a plain paragraph, identical to `\P`, so
a multi-column MTEXT arrived with nothing left to lay columns out from —
and the writer sent every break back as `\P`, collapsing the columns for
good on round-trip. `MTextParagraph::starts_column` now carries it.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

Cargo.lock

@@ -73,7 +73,7 @@ checksum = "366ffbaa4442f4684d91e2cd7c5ea7c4ed8add41959a31447066e279e432b618"
 [[package]]
 name = "acadrust"
 version = "0.4.0"
-source = "git+https://github.com/OpenAEC-Foundation/acadifc?branch=main#769741db529601ada625570710db7ed56f2cecd6"
+source = "git+https://github.com/OpenAEC-Foundation/acadifc?branch=main#e1b8508fe2a3a22bea18dfbb0e5c21578286d76f"
 dependencies = [
  "ahash 0.8.12",
  "anyhow",
@@ -3179,7 +3179,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "0b577e2d69827c4740cba2b52efaad1c4cc7c73042860b199710b3575c68438d"
 dependencies = [
  "bytecount",
- "memchr 1.0.2",
+ "memchr 2.8.3",
  "nom 8.0.0",
 ]