feat: Tailwind CSS integration

[next-devin]

Summary

• Auto-detection: ntk watch and ntk tailwind auto-detect Tailwind v4 (@import "tailwindcss" in css/input.css) or v3 (tailwind.config.js), find the binary (./tailwindcss, PATH, or npx), and detect scripts/sass-compat.py post-processor
• ntk tailwind command: One-shot compile + sass-compat + push. Supports --minify for production builds
• ntk watch integration: Spawns Tailwind CLI as a background watcher, runs sass-compat on CSS output changes before pushing — eliminates the race condition between Tailwind compilation and file push

Config

Optional tailwind: section in config.yml (auto-detected if not present):

development:
  tailwind:
    input: css/input.css
    output: assets/main.css
    binary: ./tailwindcss
    sass_compat: scripts/sass-compat.py

Test plan

• 21 new tests (detection, compilation, watch lifecycle) — all pass
• 41 existing tests unaffected — all pass (62 total)
• Verified detection against live Spark theme (v4 marker, local binary, sass-compat all detected)
• Manual test: ntk watch in Spark directory with Tailwind changes
• Manual test: ntk tailwind --minify in Spark directory

🤖 Generated with Claude Code