docs: fix outdated documentation (automated weekly drift check)

- CLAUDE.md: Update `global_config.llm_config.default_model` to `global_config.default_llm.default_model`
  - Evidence: `common/config_models.py` defines `DefaultLlm` (containing `default_model`) and `LlmConfig` (containing `retry`, `cache_enabled`) separately.
- manual_docs/branch_comparison.md: Change `pytest-asyncio` support for `main` from `✅` to `❌`
  - Evidence: `pyproject.toml` dependencies do not include `pytest-asyncio`, and `uv run pip list` confirms it is not installed.
- docs/content/docs/index.mdx: Replace `make setup` with `uv sync`
  - Evidence: `Makefile` does not contain a `setup` target.
- docs/content/docs/index.mdx: Replace `uv run python src/main.py` with `uv run python main.py`
  - Evidence: `main.py` resides in the project root, not in `src/`.

Co-authored-by: Miyamura80 <38335479+Miyamura80@users.noreply.github.com>

Author: google-labs-jules[bot]