Remove unused docker CLI client (#2576)
* Move CLAUDE.md to AGENTS.md, update contents, and a symlink to preserve
CC behavior
* Remove the unused docker CLI client
The newer SDK client has been default for nearly 6 months. Also removes
~11 minutes of integration tests from CI.
* remove an old test
* Remove more dead code
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Co-authored-by: Michael Dwan <mdwan@cloudflare.com>
