- Migrated process spawning from `cspawn` to `spawnGroup` and `spawnAttached` APIs with explicit resource management using TypeScript's `using` statement.
- Refactored `ChildProcess` class to support process group management with new `isProcessGroup` getter and `[Symbol.dispose]()` method for automatic cleanup.
- Removed `cspawn` from public API exports in pi-utils, replacing it with `spawnGroup` and `spawnAttached` functions.
- Simplified `ChildProcess.kill()` method signature by removing signal parameter and eliminated `killAndWait()` method in favor of async disposable pattern.
- Converted `killChild` function to async implementation using Bun's `$` template and sleep-based polling for process termination.