fix(kernel-env): retry uv pip install with --refresh on stale cache (#1051)

* fix(kernel-env): retry uv pip install with --refresh on failure

When uv's cached package index is stale, installing recently-published
versions (e.g. nightly pre-releases) fails with "no version found". Retry
once with --refresh to force a fresh index fetch, with no perf impact on
the happy path.

* fix(kernel-env): improve retry robustness and drop unrelated schema diffs

- Clone install_args and insert --refresh instead of slicing by magic index
- Log first-attempt stderr before retrying for easier debugging
- Revert unrelated generated schema changes (webdriver ACL removal)

Author: rgbkrk

crates/kernel-env/src/uv.rs

@@ -226,6 +226,27 @@ pub async fn prepare_environment_in(
         .output()
         .await?;
 
+    // If install failed, retry once with --refresh to bypass stale index cache.
+    // This handles cases where a recently-published version (e.g. a nightly pre-release)
+    // isn't found because uv's cached package index is stale.
+    let install_output = if !install_output.status.success() {
+        let first_stderr = String::from_utf8_lossy(&install_output.stderr);
+        info!(
+            "uv pip install failed, retrying with --refresh. First attempt stderr: {}",
+            first_stderr
+        );
+        let mut retry_args = install_args.clone();
+        retry_args.insert(2, "--refresh".to_string());
+        tokio::process::Command::new(&uv_path)
+            .args(&retry_args)
+            .stdout(Stdio::piped())
+            .stderr(Stdio::piped())
+            .output()
+            .await?
+    } else {
+        install_output
+    };
+
     if !install_output.status.success() {
         tokio::fs::remove_dir_all(&venv_path).await.ok();
         let stderr = String::from_utf8_lossy(&install_output.stderr);