Three independent sub-projects (one per Pearl), each an atomic commit,
each running in its own git worktree (sp6-pearl-2/3/5). Pearl 2 expands
compute_adaptive_budgets() to per-branch [f32;4] arrays + trunk-mean
scalars, dispatches branch-correction SAXPY sub-launches. Pearl 3
replaces noise_sigma: f32 with noise_sigma_per_branch: [f32;4] in
ExperienceCollectorConfig and extends add_advantage_noise to per-branch
lookup. Pearl 5 adds 4-branch tau buffer triplets to GpuIqnHead, runs
4 IQN forward passes per step (Approach B), each contributing
iqn_trunk/4 to prevent 4x gradient accumulation.
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>