Add March 2026 programming: 10 new metcons + 22 sessions

New metcons (OP-011 through OP-020):
- Sweet Rust, Quick Birch, Long Copper, Thick Iron, Spicy Gravel
- Sharp Frost, Heavy Brick, Sweet Ash, Dark Ember, Quick Salt

22 sessions covering Mar 2-31 with weekly template:
- Monday: Heavy lower body + short/interval metcon
- Tuesday: Engine/capacity + long metcon
- Wednesday: Press/upper body + moderate metcon
- Friday: Pull/posterior chain + grind metcon
- Saturday: Olympic skill + weekend grinder

Key retests in weeks 3-4 for progress tracking:
- OP-001, OP-002, OP-004, OP-008, OP-009, OP-010

Also adds audit-metcons.mjs script for scaling integrity validation.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Author: OneMuppet