feat(temple): sacred mathematical functions (V41) (#415)

Advanced φ-based operations for Trinity S³AI:

 sacred_functions.zig (470 LOC):
 - φ constants: PHI_INV, PHI_SQ, PHI_INV_SQ, PHI_INV_CUBED
 - φ-exponential/logarithm/power/root functions
 - Sacred activation functions: sigmoid, tanh, GELU
 - Sacred matrix operations: matmul, transpose (φ-normalized)
 - Sacred LR schedules: φ-decay, φ-cosine, φ-warmup
 - Sacred initialization: Xavier-like, Kaiming-like with φ
 - Ternary quantization: threshold, quantize, dequantize
 - Sacred loss functions: MSE, cross-entropy with φ
 - Numerical stability: log-sum-exp, softmax with φ
 - Number theory: Fibonacci verification, Binet's formula
 - Trinity Identity verification: φ² + 1/φ² = 3

Total: ~470 new LOC
Tests: 23/23 passing (11 sacred_functions + 12 sacred_math)
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Author: Antigravity Agent