Add gaming deals Matrix bot

Implements a Matrix bot that posts PC gaming deals and free game alerts:
- CheapShark API integration (Steam, GOG, Humble, GMG) polled every 2 hours
- Epic Games Store free games detection polled daily
- IsThereAnyDeal historical low price flagging (optional)
- SQLite deduplication with 30-day pruning
- First-run population (records existing deals without posting)
- Matrix-flavored HTML + plain text fallback messages
- Dockerfile for containerized deployment

https://claude.ai/code/session_01LPpSZFfyh6vdV5HGFWjoQX

README.md

@@ -1 +1,51 @@
-# Pastel
+# Pastel
+
+A Matrix bot that posts gaming deals and free game alerts to a specified Matrix room.
+
+Deals are sourced from PC/digital storefronts only (Steam, GOG, Humble Store, GreenManGaming, Epic Games Store) — universally accessible regardless of region.
+
+## Data Sources
+
+- **CheapShark** — polled every 2 hours for top deals across Steam, GOG, Humble Store, and GreenManGaming
+- **Epic Games Store** — polled daily for free game promotions
+- **IsThereAnyDeal** (optional) — flags deals that are at an all-time historical low price
+
+## Quick Start
+
+1. Copy `.env.example` to `.env` and fill in your Matrix credentials and room ID
+2. Run with Docker:
+
+```bash
+docker build -t pastel .
+docker run --env-file .env -v pastel-data:/data pastel
+```
+
+Or run directly with Python 3.12+:
+
+```bash
+pip install -r requirements.txt
+python -m gaming_deals_bot
+```
+
+## Configuration
+
+All configuration is via environment variables (see `.env.example`):
+
+| Variable | Required | Default | Description |
+|---|---|---|---|
+| `MATRIX_HOMESERVER_URL` | Yes | — | Matrix homeserver URL |
+| `MATRIX_BOT_USER_ID` | Yes | — | Bot's Matrix user ID |
+| `MATRIX_BOT_ACCESS_TOKEN` | Yes | — | Bot's access token |
+| `MATRIX_DEALS_ROOM_ID` | Yes | — | Room ID to post deals in |
+| `ITAD_API_KEY` | No | — | IsThereAnyDeal API key for historical low detection |
+| `MIN_DEAL_RATING` | No | 80 | Minimum CheapShark deal rating (0-100) |
+| `MIN_DISCOUNT_PERCENT` | No | 50 | Minimum discount percentage |
+| `MAX_PRICE_USD` | No | 20 | Maximum sale price in USD |
+| `DATABASE_PATH` | No | deals.db | Path to SQLite database file |
+
+## Behavior
+
+- **First run**: fetches current deals and records them in the database without posting (avoids spamming the room with existing deals)
+- **Deduplication**: deals are tracked by game ID + timestamp; duplicates are never reposted
+- **Pruning**: deals older than 30 days are pruned from the database so they can be reposted if they return
+- **One message per deal**: each deal is posted individually so messages are independently linkable and dismissible