✨ feat: implement core Optimus library for JSON mapping and validation

- 🎨 add Spring-like decorators (@JsonSerialize, @JsonDeserialize, etc.)
- ⚙️ implement JsonMapper and metadata storage for transformations
- 🧪 add comprehensive test suite using Vitest
- 📝 add README, CONTRIBUTING, and API documentation
- 👷 setup GitHub Actions CI workflow
- 🔧 configure TypeScript and project settings

tsconfig.json

@@ -0,0 +1,40 @@
+{
+  // Visit https://aka.ms/tsconfig to read more about this file
+  "compilerOptions": {
+    // File Layout
+    "rootDir": "src",
+    "outDir": "dist",
+
+    // Environment Settings
+    "module": "CommonJS",
+    "target": "ES2020",
+    "lib": ["ESNext"],
+    "types": ["node"],
+
+    // Other Outputs
+    "sourceMap": true,
+    "declaration": true,
+    "declarationMap": true,
+
+    // Stricter Typechecking Options
+    "noUncheckedIndexedAccess": true,
+    "exactOptionalPropertyTypes": true,
+
+    // Style Options
+    "noImplicitReturns": true,
+    "noImplicitOverride": true,
+    "noUnusedLocals": true,
+    "noUnusedParameters": true,
+    "noFallthroughCasesInSwitch": true,
+
+    // Recommended Options
+    "strict": true,
+    "strictPropertyInitialization": false,
+    "isolatedModules": true,
+    "skipLibCheck": true,
+
+    "experimentalDecorators": true
+  },
+  "include": ["src/**/*"],
+  "exclude": ["node_modules", "dist", "src/**/*.test.ts", "src/example.ts"]
+}