feat(core): replace Claude CLI with pure TS css-generator in Phase 1A

Phase 1A token extraction was spending ~3 min spawning Claude CLI for a
100% mechanical task (read JSON + template CSS). Now generateGlobalsCss()
does it deterministically in <1s with zero LLM cost.

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

Author: lucianfialho