✓ CDP engine (Chrome/Chromium launch + connect)
✓ Compression layer (semantic summaries, element cache, snapshot versioning)
✓ Security sanitizer (injection guard, hidden filter)
✓ Typed error recovery (6 error types)
✓ Full Shadow DOM access
✓ Primitive API: snapshot, click, type, extract, observe
✓ High-level: run(goal, llm)
✓ Observability trace (token counts, action log)
✓ LLM-agnostic (works with any model)