Add lock files for package management and update architecture documentation

- Introduced bun.lock and package-lock.json to manage dependencies for the project.
- Enhanced backend API architecture documentation with additional security and documentation guidelines.
- Made minor formatting adjustments across various files for consistency and clarity.

backend-api/index.ts

@@ -1 +1 @@
-console.log("Hello via Bun!");
+console.log('Hello via Bun!');