- New docs/extensions.md: command reference for all 9 specify extension
commands and 3 specify extension catalog commands, plus catalog
resolution order, extension configuration, and FAQ
- docs/integrations.md: add FAQ section covering single-integration limit,
file preservation, key discovery, CLI vs IDE requirements, upgrade vs switch
- docs/toc.yml: add Extensions under Reference section
- README.md: update integration and extension links to published docs site
- New docs/integrations.md: canonical reference for supported agents table
(with keys), list/install/uninstall/switch/upgrade commands, file
preservation behavior, and integration-specific options
- README.md: replace inline agents table with summary + link to new page;
normalize heading to 'Supported AI Coding Agent Integrations'
- docs/toc.yml: add top-level 'Reference' section with Integrations page
- docs/upgrade.md: fix broken cross-reference, update terminology
- CONTRIBUTING.md: update anchor link to new heading
