docs: add censored Archimax fitting example

[lrnv]

Closes #361.\n\nAdds an executable documentation example for fitting an Archimax dependence parameter from observations subject to variable-specific right censoring. The example derives the four likelihood contributions from the public conditioning and survival-copula APIs, explains why a marginal censored wrapper alone is insufficient, and visualizes the observed censoring geometry.

[lrnv]

Documentation runtime audit completed. The routine Documenter job went from 11m58s to 4m17s while retaining execution of every documentation example and PR preview deployment.\n\nMain changes:\n- routine docs no longer execute the Julia/R benchmark matrix; it remains available through the manual Documenter workflow with the �enchmarks input;\n- the docs environment is instantiated without the unused --code-coverage compilation mode from julia-docdeploy;\n- one-shot documentation code is built at -O0, which reduced template expansion from roughly 3 minutes to 1m57s without disabling evaluation;\n- oversized illustrative fitting samples were reduced while preserving all exercised API paths.\n\nThe remaining time is mostly genuine page execution (~1m57s), Vitepress rendering (~46s), preview publication (~40-50s), and runner/cache setup. Going materially below four minutes would likely require dropping PR previews or skipping executable pages, which does not seem like a worthwhile trade-off.