chore: migrate to pnpm workspaces monorepo with Turborepo

- Restructure directories: apps/api, apps/admin, apps/website
- Add root pnpm-workspace.yaml, turbo.json, .prettierrc, .gitignore
- Rename packages to @inkreach/api, @inkreach/admin, @inkreach/website
- Add shared packages: packages/tsconfig, packages/shared-types
- Add pnpm.onlyBuiltDependencies for native builds
- Update docs: README.md, structs.md
- All three projects build successfully

apps/api/jest.config.js

@@ -0,0 +1,15 @@
+module.exports = {
+  moduleNameMapper: {
+    '^@/(.*)$': '<rootDir>/src/$1',
+  },
+  testEnvironment: 'node',
+  moduleFileExtensions: ['js', 'json', 'ts'],
+  rootDir: 'src',
+  testRegex: '.*\\.spec\\.ts$',
+  transform: {
+    '^.+\\.(t|j)s$': 'ts-jest',
+  },
+  collectCoverageFrom: ['**/*.(t|j)s'],
+  coverageDirectory: '../coverage',
+  coveragePathIgnorePatterns: ['/node_modules/', '/test/'],
+};