refactor: replace pastel-wasm with pure TypeScript color engine

Removes the @valknarthing/pastel-wasm WASM dependency and replaces it
with a self-contained TypeScript implementation of all color operations
(parsing, conversion, manipulation, gradients, palette generation).
Adds eslint-plugin-react-hooks which was missing from devDependencies.

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

package.json

@@ -19,7 +19,6 @@
     "@ffmpeg/util": "^0.12.2",
     "@imagemagick/magick-wasm": "^0.0.38",
     "@tanstack/react-query": "^5.90.21",
-    "@valknarthing/pastel-wasm": "^0.1.0",
     "class-variance-authority": "^0.7.1",
     "clsx": "^2.1.1",
     "cmdk": "^1.1.1",
@@ -50,6 +49,7 @@
     "@types/react-dom": "^19.2.3",
     "eslint": "^9.21.0",
     "eslint-config-next": "^15.1.7",
+    "eslint-plugin-react-hooks": "^7.0.1",
     "postcss": "^8.5.6",
     "shadcn": "^3.8.5",
     "tailwind-scrollbar": "^4.0.2",