getRawComposioToolBySlug relabelled every client error, including an
invalid API key (401), as ComposioToolNotFoundError. Map only 404/400 to
not-found and wrap the rest in a new ComposioToolFetchError that keeps
the client error as cause. Toolkits.getToolkitBySlug compared against
the OpenAI APIError class, so its not-found branch never fired; import
the Composio client class instead. Python mirrors the mapping: an
unknown slug raises ToolNotFoundError (now a NotFoundError), anything
else propagates the composio_client error unchanged.
PRDE-1613
Claude-Session: https://claude.ai/code/session_017HtbhwMAKcfebo8HyXWa5s
jkomyno