Initial scaffold: React 19 + Vite + TypeScript + Tailwind CSS v4 + Storybook 10

Design system and component library for the Research Synthesiser. Includes:
- Tailwind CSS v4 with @theme-based design tokens from the existing synthesiser
- Storybook 10.4 with MCP, a11y, docs, and vitest addons
- ESLint + Prettier with Tailwind class sorting
- Button component as pipeline validation
- CLAUDE.md with project principles and conventions
- ARCHITECTURE.md as living architecture document
- Penpot and Storybook MCP server configuration

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

eslint.config.js

@@ -0,0 +1,23 @@
+// For more info, see https://github.com/storybookjs/eslint-plugin-storybook#configuration-flat-config-format
+import storybook from "eslint-plugin-storybook";
+import eslintConfigPrettier from "eslint-config-prettier";
+
+import js from '@eslint/js'
+import globals from 'globals'
+import reactHooks from 'eslint-plugin-react-hooks'
+import reactRefresh from 'eslint-plugin-react-refresh'
+import tseslint from 'typescript-eslint'
+import { defineConfig, globalIgnores } from 'eslint/config'
+
+export default defineConfig([globalIgnores(['dist']), {
+  files: ['**/*.{ts,tsx}'],
+  extends: [
+    js.configs.recommended,
+    tseslint.configs.recommended,
+    reactHooks.configs.flat.recommended,
+    reactRefresh.configs.vite,
+  ],
+  languageOptions: {
+    globals: globals.browser,
+  },
+}, ...storybook.configs["flat/recommended"], eslintConfigPrettier])