refactor: migrate key packages from tsup to rollup for build consistency

Migrate icon packages and main platform packages to rollup while maintaining
tsup for simpler core packages:

Packages migrated to rollup:
- packages/core/icons - Core SVG icon definitions
- packages/html/html-icons - HTML-specific icon components
- packages/html/html - Main HTML package
- packages/react/react-icons - React icon components

Packages remaining on tsup:
- Core packages (media, media-store, playback-engine) - Simple TypeScript builds
- Helper packages (*-media-elements, *-media-store) - Working fine with tsup
- React Native packages - Per exclusion request

Benefits:
- Consistent build tooling across icon and platform packages
- Better asset handling capability for future SVG/CSS requirements
- Maintained simplicity for packages that don't need advanced features
- All packages build successfully with proper CommonJS/ESM outputs

🤖 Generated with [Claude Code](https://claude.ai/code)

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

packages/html/html-icons/tsconfig.build.json

@@ -0,0 +1,11 @@
+{
+  "extends": "./tsconfig.json",
+  "compilerOptions": {
+    "declaration": true,
+    "declarationDir": "dist",
+    "emitDeclarationOnly": true,
+    "outDir": "dist",
+    "skipLibCheck": true
+  },
+  "exclude": ["dist", "node_modules"]
+}