refactor(env): route Shirabe's own env reads through the shim

These sites have no PHP counterpart to mirror, so they read std::env
directly. Going through the shim's getenv() keeps every environment
read in one place and lets a lint forbid the direct form.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

1 files changed, 1 insertions, 1 deletions

diff --git a/crates/shirabe-php-rpc/src/composer_runtime.rs b/crates/shirabe-php-rpc/src/composer_runtime.rs
index d5024fad..afa7c6e1 100644
--- a/crates/shirabe-php-rpc/src/composer_runtime.rs
+++ b/crates/shirabe-php-rpc/src/composer_runtime.rs
@@ -51,7 +51,7 @@ fn path_to_string(directory: std::path::PathBuf) -> anyhow::Result<String> {
 /// The checkout that stands in for the bundle, if `OVERRIDE_ENV` names one. Both the worker and
 /// the Rust side read the runtime from there instead.
 fn override_directory() -> anyhow::Result<Option<std::path::PathBuf>> {
-    let Some(directory) = std::env::var_os(OVERRIDE_ENV) else {
+    let Some(directory) = shirabe_php_shim::getenv(OVERRIDE_ENV) else {
         return Ok(None);
     };
     let directory = std::path::PathBuf::from(directory);