fix(e2e): prevent timeout from hanging by exiting immediately

When timeout occurs, immediately kill the process and exit the loop
without waiting for stdout/stderr pipes to drain. This prevents tests
from hanging indefinitely on platforms where child processes don't
close pipes properly after being killed.

The previous implementation waited for pipes to close after timeout,
which could hang if the process tree (sh -> vite -> node) didn't
terminate cleanly.

Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>

Author: branchseer

crates/vite_task_bin/tests/e2e_snapshots/main.rs

@@ -261,15 +261,14 @@ async fn run_case_inner(tmpdir: &AbsolutePath, fixture_path: &Path, fixture_name
                         termination_state = Some(TerminationState::Exited(result.unwrap()));
                     }
                     _ = &mut timeout, if termination_state.is_none() => {
-                        // Timeout - kill the process
+                        // Timeout - kill the process and exit immediately
                         let _ = child.kill().await;
-                        termination_state = Some(TerminationState::TimedOut);
+                        break &TerminationState::TimedOut;
                     }
                 }
 
                 // Exit conditions:
                 // 1. Process exited and all output drained
-                // 2. Timed out and all output drained (after kill, pipes close)
                 if let Some(termination_state) = &termination_state
                     && stdout_done
                     && stderr_done