# Objective
Opening a file laods it twice. `decode_file_text` builds the whole file
as a `String`, and that `String` stays alive alongside the finished rope
while `text::Buffer::new` copies it in. The `Vec` behind it grows by
doubling, so it also commits up to nearly the file's size again in
capacity it never uses.

Partially addresses #27283.

## Solution

Add `decode_file_text_to_rope`, which streams the file in 1 MB blocks
straight into a `Rope`, validating UTF-8 and normalizing line endings as
it goes. The file is never fully held as a `String`.

`LoadedFile::text` becomes a `Rope` carrying the `LineEnding` detected
before normalizing, so `buffer_store` calls `Buffer::new_normalized`.

## Testing

On a 729 MB SQL dump, peak memory fell 25% and CPU fell around 28%.
tested on 5950x, win11.

Release Notes:

- Improved memory use when opening large files, reducing peak memory
during load by roughly the size of the file itself.