Add AdamW–MuonClip nanoGPT WeightWatcher campaign

[charlesmartin14]

Summary

• add the reproducible one-head FineWeb-Edu nanoGPT campaign
• compare exactly AdamW and MuonClip over five paired seeds
• run seed 1337 first, with provisional analysis before the other seeds
• record WeightWatcher alpha and raw_alpha from one fix_fingers="clip_xmax" call
• retain ERG gap, correlation traps, detX, performance metrics, strict restart/provenance, and Mac /tmp workflow

Validation

• 151 passed in the complete baseline/nanogpt_one_head/tests suite
• production doctor passed AdamW and MuonClip checkpoint/resume
• real WeightWatcher smoke passed with six corrected alphas and six raw alphas