release: v2.1.2 — landing page TSX output, brand voice integration, docs update

- Landing page generator defaults to Next.js TSX + Tailwind CSS (4 design styles)
- Brand voice analyzer integrated into landing page generation workflow
- CHANGELOG, CLAUDE.md, README.md updated for v2.1.2
- All 13 plugin.json + marketplace.json bumped to 2.1.2
- Gemini/Codex skill indexes re-synced
- Backward compatible: --format html preserved, no breaking changes

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

product-team/.codex/instructions.md

@@ -29,7 +29,17 @@ python3 product-team/product-strategist/scripts/okr_cascade_generator.py --help
 | Landing pages | landing-page-generator |
 | SaaS boilerplate | saas-scaffolder |
 
+## Cross-Domain Workflows
+
+**Landing page + brand voice:** Before generating landing pages, run the brand voice analyzer to match copy tone:
+```bash
+python3 marketing-skill/content-production/scripts/brand_voice_analyzer.py brand_copy.txt --format json
+python3 product-team/landing-page-generator/scripts/landing_page_scaffolder.py config.json --format tsx
+```
+Voice profile maps to design styles: formal+professional→enterprise, casual+friendly→bold-startup, professional+authoritative→dark-saas, casual+conversational→clean-minimal.
+
 ## Rules
 
 - Load only 1-2 skills per request — don't bulk-load
 - Use Python tools for scoring and analysis
+- Landing page scaffolder defaults to TSX output (Next.js + Tailwind). Use `--format html` for standalone HTML.