Share one /api/models fetch via useModelCaps cache, mount ModelSelectModal
only when open, stop double fetchModelAliases on CLI tool cards, and resolve
provider icons through a session 404 cache with missing PNGs + loading=lazy.
Also include Claude Exa MCP toggle (claude-settings + ClaudeToolCard) that
was already in the working tree.
Co-authored-by: Cursor <cursoragent@cursor.com>