- Add BotUIInstance struct to start botui alongside botserver
- Update E2ETestContext to start botui and use its URL as base_url
- Add start_botui() method to TestContext
- Fix harness to use env vars BOTUI_PORT and BOTSERVER_URL for botui
- Update harness to use debug build by default
- Add SKIP_LLM_SERVER env var to skip local LLM server in tests
- Make stack_path absolute and canonicalize botserver paths
- Removed E2E_TESTING_PLAN.md, README_E2E_TESTING.md, TEMP_STACK_SETUP.md from root
- All documentation now in gb/botbook/src/17-testing/
- Updated PROMPT.md v7.0 to forbid root .md files
- PROMPT.md is now the source of truth for testing patterns
- Developers refer to botbook and PROMPT.md, not scattered .md files