Capture Phase 3b Jmax1 Gram matrix

[mdheller]

Summary

Captures Phase 3b: Jmax=1 Gram matrix in the Phase 3a 14-label registry order.

Added

• manuscripts/lane-temporal-mechanics-jmax1/phase3b-gram-matrix/source.md
  • states normalized Peter-Weyl/Wigner Gram convention;
  • records G = I_14;
  • verifies Jmax=1/2 regression sub-block at indices [0,1,2,4,5] is I_5;
  • preserves no-transfer/no-spectrum/no-physical-interpretation claim boundary.
• manuscripts/lane-temporal-mechanics-jmax1/phase3b-gram-matrix/gram_matrix.json
  • machine-readable identity Gram matrix in Phase 3a basis order.

Claim discipline

This PR does not claim:

• transfer matrix;
• temporal kernel entries;
• spectrum;
• vacuum decomposition;
• coefficient graph;
• beta trend;
• scale proxy;
• physical mass interpretation;
• continuum/infinite-volume/Clay result.

Next target

Phase 3c: Jmax=1 -> Jmax=1/2 truncation regression after constructing the Jmax=1 operator/matrix entries.