perf(json-file): buffer schema file reads in FileRetriever

serde_json::from_reader issues one read() syscall per byte against an
unbuffered Reader. FileRetriever passed a raw File straight through,
so resolving the composer-schema.json $ref read its ~71KB contents
one byte at a time (twice per require, since schema validation runs
both before and during the update).

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

1 files changed, 1 insertions, 1 deletions

diff --git a/crates/shirabe/src/json/json_file.rs b/crates/shirabe/src/json/json_file.rs
index b95732fa..075e1f64 100644
--- a/crates/shirabe/src/json/json_file.rs
+++ b/crates/shirabe/src/json/json_file.rs
@@ -593,7 +593,7 @@ impl jsonschema::Retrieve for FileRetriever {
         match uri.scheme().as_str() {
             "file" => {
                 let file = std::fs::File::open(uri.path().as_str())?;
-                Ok(serde_json::from_reader(file)?)
+                Ok(serde_json::from_reader(std::io::BufReader::new(file))?)
             }
             scheme => Err(format!("Unknown scheme {scheme}").into()),
         }