docs: Add CNN flatten mode technical analysis

Comprehensive analysis of single-pass CNN shader architecture:
- Full flatten (3 layers): 544 bytes/thread register pressure - NOT recommended
- Partial flatten (layers 1+2): 288 bytes/thread - marginal benefit
- Current multi-pass: Optimal for GPU occupancy and maintainability

Recommendation: Keep current 3-pass architecture.
Alternative size optimizations: weight quantization, kernel reduction.

handoff(Claude): CNN flatten analysis documented

0 files changed, 0 insertions, 0 deletions