docs: README AG2 badge says '1.0 beta' but the repo pins stable ag2==1.0.1

## Problem `README.md` advertises AG2 as a beta dependency: ```markdown [](https://github.com/ag2ai/ag2) ``` The repo does not depend on a beta. `pyproject.toml:28` pins a stable release: ```toml "ag2[a2a,openai,tracing]==1.0.1", ``` Same pin in `pyproject.toml:55` (`ag2[gemini]==1.0.1`), `pyproject.toml:58` (`ag2[anthropic]==1.0.1`), and `requirements.txt`. `ag2 1.0.1` is a normal stable release on PyPI — uploaded 2026-07-29, `"yanked": false`, not a prerelease. Upstream shipped 1.0.0 ahead of it, with release notes reading: > AG2 v1 is here! The protocol-driven framework we started building as `autogen.beta` in v0.12 is now the mainline framework. So the `1.0 beta` label is stale. The README is also the PyPI project description (see `.claude/rules/docs.md`), which makes "beta" the first signal a prospective user gets about the backbone dependency. ## What to do Update the badge to reflect the pinned stable version, e.g.: ```markdown [](https://github.com/ag2ai/ag2) ``` If the badge should track the minor line rather than the exact patch, `AG2-1.0-green` works too — the point is that it should not say `beta`. ## Verify ```bash grep -n "ag2" pyproject.toml requirements.txt grep -n "img.shields.io/badge/AG2" README.md ``` Confirm the pinned version against PyPI rather than trusting this issue's text: ```bash python -m pip index versions ag2 ```