Add Flask backend API, React frontend dashboard, and Render deployment config

[echska]

Motivation

• Provide a minimal full-stack parental control prototype with a lightweight backend API and a responsive frontend dashboard for viewing alerts, calls, messages, and location data.
• Enable easy local/container deployment and cloud previews by including a Dockerfile for the backend and a render.yaml for Render static + web services.
• Offer simple file-backed storage for synced device data to facilitate development without a database dependency.

Description

• Add a Flask backend in parental-control-system/backend with main.py exposing POST /api/v1/sync, GET /api/v1/data/<category>, and a /health endpoint, plus per-category vault files and a Dockerfile and requirements.txt for containerized deployment.
• Add a React frontend in parental-control-system/frontend including package.json, Tailwind config, src pages/components (Dashboard, CallsTable, MessagesTable, LocationsMap, LocationsTimeline, AlertsPanel, and placeholders for router/WhatsApp/Instagram), and an API service wrapper in src/services/api.js pointing to an environment-configurable backend URL.
• Include initial empty vault JSON files, a .gitignore entry for frontend node_modules, and render.yaml with two services (backend web using Docker and frontend static site) plus PR preview settings and environment variables.

Testing

• No automated tests or CI test suite were added or executed as part of this change.
• The backend includes a GET /health endpoint intended for runtime health checks and platform readiness probes.
• Render preview generation is enabled via render.yaml to allow platform-based build verification for pull request previews.

---

Codex Task

[chatgpt-codex-connector]

💡 Codex Review

Here are some automated review suggestions for this pull request.

Reviewed commit: f3f882e408

ℹ️ About Codex in GitHub

Your team has set up Codex to review pull requests in this repo. Reviews are triggered when you

• Open a pull request for review
• Mark a draft as ready
• Comment "@codex review".

If Codex has suggestions, it will comment; otherwise it will react with 👍.

Codex can also answer questions or update the PR. Try commenting "@codex address that feedback".