feat: add monorepo configuration and shared packages structure

Root-level setup:
- package.json with Turborepo scripts
- pnpm-workspace.yaml for workspace management
- turbo.json for build pipeline
- Common config files (.nvmrc, .prettierrc, .editorconfig)

Shared packages (packages/):
- @manacore/shared-types - Common TypeScript types
- @manacore/shared-supabase - Unified Supabase client
- @manacore/shared-utils - Date, string, async utilities
- @manacore/shared-ui - React Native UI components (placeholder)

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

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

packages/shared-ui/src/index.ts

@@ -0,0 +1,24 @@
+/**
+ * Shared React Native UI components for Manacore monorepo
+ *
+ * This package will contain common UI components used across all mobile apps.
+ *
+ * Planned components:
+ * - Button
+ * - Text
+ * - Input
+ * - Card
+ * - Modal
+ * - Loading indicators
+ * - Icons
+ */
+
+// Placeholder export until components are migrated
+export const SHARED_UI_VERSION = '0.1.0';
+
+// Future exports will include:
+// export { Button } from './components/Button';
+// export { Text } from './components/Text';
+// export { Input } from './components/Input';
+// export { Card } from './components/Card';
+// export { Modal } from './components/Modal';