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-types/package.json

@@ -0,0 +1,18 @@
+{
+  "name": "@manacore/shared-types",
+  "version": "0.1.0",
+  "private": true,
+  "description": "Shared TypeScript types for Manacore monorepo",
+  "main": "./src/index.ts",
+  "types": "./src/index.ts",
+  "exports": {
+    ".": "./src/index.ts"
+  },
+  "scripts": {
+    "type-check": "tsc --noEmit",
+    "clean": "rm -rf dist"
+  },
+  "devDependencies": {
+    "typescript": "^5.9.2"
+  }
+}

packages/shared-types/src/index.ts

@@ -0,0 +1,47 @@
+/**
+ * Shared types for Manacore monorepo
+ *
+ * This package contains common TypeScript types used across all projects.
+ */
+
+// Common user types
+export interface User {
+  id: string;
+  email: string;
+  created_at: string;
+  updated_at: string;
+}
+
+// Common API response types
+export interface ApiResponse<T> {
+  data: T | null;
+  error: ApiError | null;
+}
+
+export interface ApiError {
+  message: string;
+  code?: string;
+  status?: number;
+}
+
+// Pagination types
+export interface PaginationParams {
+  page?: number;
+  limit?: number;
+  offset?: number;
+}
+
+export interface PaginatedResponse<T> {
+  data: T[];
+  total: number;
+  page: number;
+  limit: number;
+  hasMore: boolean;
+}
+
+// Supabase common types
+export interface SupabaseConfig {
+  url: string;
+  anonKey: string;
+  serviceRoleKey?: string;
+}

packages/shared-types/tsconfig.json

@@ -0,0 +1,17 @@
+{
+  "compilerOptions": {
+    "target": "ES2020",
+    "module": "ESNext",
+    "moduleResolution": "bundler",
+    "lib": ["ES2020"],
+    "strict": true,
+    "esModuleInterop": true,
+    "skipLibCheck": true,
+    "forceConsistentCasingInFileNames": true,
+    "declaration": true,
+    "declarationMap": true,
+    "outDir": "./dist"
+  },
+  "include": ["src/**/*"],
+  "exclude": ["node_modules", "dist"]
+}