Documents the SP11 sharpe-degradation root cause investigation:
- 35db31089: symmetric reward cap (THE bug)
- 348f6078b: plan_isv symmetric clamp mirrors (4 sites)
- b92dcc3df: diagnostic instrumentation cleanup
- this commit: close-out
New memory pearl: pearl_symmetric_clamp_audit
Distinct from pearl_bounded_modifier_outputs_require_structural_activation:
- That pearl: model OUTPUTS need structural activation (sigmoid/tanh)
- This pearl: intermediate kernel scalars need bilateral fminf/fmaxf
Both share: bounded contracts must be enforced structurally.
Audit doc: cross-references bug, fix, validation smoke, both pearls.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>