feat(api): Created openapi based pubic API contracts

- made DTOs
- created an api-client

packages/api-client/package.json

@@ -0,0 +1,13 @@
+{
+  "name": "@omnia/api-client",
+  "version": "0.0.0",
+  "private": true,
+  "type": "module",
+  "exports": {
+    ".": "./dist/index.js"
+  },
+  "dependencies": {
+    "@omnia/api-contracts": "workspace:*",
+    "zod": "^4.4.3"
+  }
+}