feat: probe-based dynamic tool filtering by API key scope

[Vortiago]

• Rewrites the dynamic tool list feature to use endpoint probing instead of auth.info role/policy inspection — each unique Outline API endpoint is POSTed with a fake UUID and tools whose endpoints return 401 are hidden from the tool list
• Refactors the single dynamic_tools.py module into a dynamic_tools/ package with separate files for filtering logic, tool-endpoint mapping, and write tool names
• Simplifies the readiness probe (/ready) to a keyless HEAD request against the Outline base URL, removing the dependency on a configured API key
• Removes the auth_info() and auth_info_full() client methods, replacing them with probe_endpoint() which handles 401 vs 403 distinction and rate-limit retries
• Removes the eager auth_info() call from get_outline_client(), making client creation synchronous
• Rewrites E2E tests to cover route scopes, namespaced scopes (documents:read, documents:write, documents:create), mixed scopes, invalid keys, and both stdio and streamable-http transports with exact set matching