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/admin/tsconfig.app.json

@@ -0,0 +1,27 @@
+{
+  "extends": "@vue/tsconfig/tsconfig.dom.json",
+  "compilerOptions": {
+    "tsBuildInfoFile": "./node_modules/.tmp/tsconfig.app.tsbuildinfo",
+    "types": ["vite/client", "node"],
+
+    /* Path aliases */
+    "ignoreDeprecations": "6.0",
+    "baseUrl": ".",
+    "paths": {
+      "@/*": ["src/*"]
+    },
+
+    /* Linting */
+    "noUnusedLocals": true,
+    "noUnusedParameters": true,
+    "erasableSyntaxOnly": true,
+    "noFallthroughCasesInSwitch": true
+  },
+  "include": [
+    "src/**/*.ts",
+    "src/**/*.tsx",
+    "src/**/*.vue",
+    "src/auto-imports.d.ts",
+    "src/components.d.ts"
+  ]
+}