feat(design-tokens): extend generator with per-product Swift + Kotlin native themes
- Add generateProductSwift() and generateProductKotlin() to generate.ts
- Add PRODUCT_NATIVE_MAP for 10 products (ChronoMind, JarvisJr, PeakPulse, LysnrAI, NomGap, ActionTrail, FlowMonk, NoteLett, LocalMemGPT, LocalLLMLab)
- Output 20 native token files in generated/native/
- Fix TS type narrowing for gradient objects (line 382)
- Update DESIGN_SYSTEM_AUDIT.md with Appendix G remediation results
