Add initial project specification

README.md

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+# Raspi Telegram Live Chat
+
+Self-hosted live chat system for Raspberry Pi with embeddable website widget, web admin panel, and Telegram as the operator interface.
+
+## Goal
+
+Build a lightweight Jivo-like chat platform where visitors write through a website widget and only Telegram operators configured in the admin panel receive and answer messages.
+
+## Target device
+
+Primary target for MVP:
+
+- Raspberry Pi 3 Model B
+- Raspberry Pi OS Lite
+- Node.js backend
+- SQLite database
+- Nginx reverse proxy
+- Cloudflare Tunnel or VPS proxy for public HTTPS access
+
+Recommended OS for Raspberry Pi 3B MVP:
+
+- Raspberry Pi OS Lite 32-bit for maximum RAM economy and stability on 1 GB RAM
+- Raspberry Pi OS Lite 64-bit can be tested later if specific ARM64 packages are needed
+
+## Core components
+
+```text
+website widget -> backend API/WebSocket -> SQLite -> Telegram bot -> operators
+                         |
+                         -> web admin panel
+```
+
+## MVP modules
+
+- Backend API
+- WebSocket gateway
+- Telegram bot bridge
+- Embeddable website widget
+- Web admin panel
+- SQLite storage
+- Operator/site access rules
+- SOCKS5 proxy settings for Telegram connectivity
+
+## Required admin settings
+
+### Telegram bot
+
+- Bot token
+- Webhook or polling mode
+- Allowed operators
+- Operator-to-site mapping
+
+### SOCKS5 proxy
+
+The system must support optional SOCKS5 configuration for Telegram requests:
+
+```env
+TELEGRAM_PROXY_ENABLED=false
+TELEGRAM_PROXY_TYPE=socks5
+TELEGRAM_PROXY_HOST=127.0.0.1
+TELEGRAM_PROXY_PORT=9050
+TELEGRAM_PROXY_USERNAME=
+TELEGRAM_PROXY_PASSWORD=
+```
+
+Admin panel should expose:
+
+- Enable/disable SOCKS5
+- Proxy host
+- Proxy port
+- Username
+- Password
+- Test connection button
+
+Sensitive fields must be stored encrypted or kept in environment variables for MVP.
+
+## Website widget
+
+Example embed code:
+
+```html
+<script src="https://chat.example.com/widget.js" data-site-id="site_xxxxx"></script>
+```
+
+## Message flow
+
+```text
+Visitor sends message on website
+  -> backend receives message
+  -> backend validates site_id and origin domain
+  -> backend stores message
+  -> backend finds active operators assigned to this site
+  -> Telegram bot sends message only to those operators
+  -> operator replies in Telegram
+  -> backend maps reply to conversation
+  -> message is delivered back to website widget through WebSocket
+```
+
+## Future Android app
+
+The backend must expose stable REST and WebSocket APIs so an Android app can later work as another operator interface.
+
+Planned Android-ready API concepts:
+
+- JWT auth
+- refresh tokens
+- operator sessions
+- conversation list
+- message history
+- push-ready notification events
+- WebSocket live updates
+
+## Initial stack
+
+- Node.js
+- Fastify
+- WebSocket
+- SQLite
+- React + Vite admin panel
+- Vanilla JS widget
+- Telegram Bot API
+- Docker optional, PM2 preferred for Raspberry Pi 3B MVP
+
+## Development phases
+
+### Phase 1
+
+- Website widget
+- Backend API
+- Telegram message forwarding
+- Reply from Telegram back to website
+- SQLite persistence
+
+### Phase 2
+
+- Admin login
+- Site management
+- Operator management
+- Site/operator permissions
+- Widget embed code generator
+- SOCKS5 proxy settings
+
+### Phase 3
+
+- Conversation history
+- Dialog statuses
+- Rate limiting
+- Origin/domain validation
+- Backup script
+- Deployment guide for Raspberry Pi
+
+### Phase 4
+
+- Android app API preparation
+- Push notification model
+- Multi-device operator sessions