Update location where application looks for front-end code and templates

Update Tailwind content paths from "./client" to "./frontend" to reflect project structure.

Replit-Commit-Author: Agent
Replit-Commit-Session-Id: d5daeb82-020f-4ea2-a54f-9097efac2a63
Replit-Commit-Screenshot-Url: https://storage.googleapis.com/screenshot-production-us-central1/4119c42c-9857-448a-8c94-20be047485ba/26fcb9ff-004d-4707-9ab9-d8d4753ca199.jpg