gsDesignTune 0.1.0

New features

• gsDesignTune(), gsSurvTune(), and gsSurvCalendarTune() create a GSDTuneJob for dependency-aware scenario exploration of gsDesign::gsDesign() / gsDesign::gsSurv() / gsDesign::gsSurvCalendar() designs.
• Tune specifications tune_fixed(), tune_values(), tune_seq(), tune_int(), tune_choice(), and tune_dep() for grid/random search with dependent parameters.
• Spending UX via SpendingSpec and SpendingFamily to tune spending function families with parameter candidates.
• Parallel evaluation with {future.apply} (user controls future::plan()) and progress reporting via {progressr}.
• Standardized metric extraction (uses gsDesign::gsBoundSummary() when available), plus ranking ($best()), Pareto filtering ($pareto()), plotting ($plot()), and reporting ($report()).
• Reproducibility/audit features: stored job spec + sessionInfo(), per-configuration warnings/errors, and call reconstruction via $call_args(i); optional disk caching via cache_dir.