docs: extensively update README with detailed features, requirements, and installation instructions.

README.md

@@ -1,33 +1,98 @@
-## 1. Installation (HACS)
+# Shopping List Manager Integration for Home Assistant
 
-### Recommended
+The backend integration that powers the Shopping List Manager. Provides persistent multi-list storage, a 500+ product catalog, real-time WebSocket events, and a full API for the Lovelace card — all running natively inside Home Assistant.
+
+> **Pair with the [Shopping List Manager Card](https://github.com/thekiwismarthome/shopping-list-manager-card)** for the full UI experience.
 
 [![Open your Home Assistant instance and open this repository inside the Home Assistant Community Store.](https://my.home-assistant.io/badges/hacs_repository.svg)](https://my.home-assistant.io/redirect/hacs_repository/?owner=thekiwismarthome&repository=shopping-list-manager&category=integration)
 
-1. Click the button above.
+---
-2. Confirm adding the repository to HACS.
+
-3. Install **Shopping List Manager** from **HACS → Integrations**.
+## Features
-4. Restart Home Assistant.
+
+### 🛒 Multi-List Management
+- Create and manage multiple shopping lists
+- Private or shared lists with per-member access control
+- Active list state shared across all connected devices and users
+- List total price calculation
+
+### 📦 Items
+- Add, update, check, and delete items with quantity and unit
+- Atomic quantity increment / decrement
+- Bulk check and clear checked items
+- Per-item pricing, notes, and category assignment
+
+### 🔍 Product Catalog
+- **500+ products** (NZ-focused, extensible to AU, US, GB, CA)
+- Fuzzy search with alias matching
+- Recently-used product suggestions
+- Custom product creation
+- Allergen filtering and product substitute groups
+- Product images (WebP, 200×200px, optimised)
+
+### 🗂️ Categories
+- 13 default categories — Produce, Dairy, Meat, Bakery, Pantry, Frozen, Beverages, Snacks, Household, Health, Pet, Baby, Other
+- Category colour coding and emoji icons
+- Per-list category ordering
+
+### 💳 Loyalty Cards
+- Store loyalty and rewards card data
+- Private or shared card access per user
+
+### 🔄 Real-Time Events
+- All changes fire events on the Home Assistant bus
+- Custom WebSocket subscription proxy so **non-admin users** receive live updates without requiring HA admin privileges
 
 ---
 
-### Manual Repository URL
+## Requirements
 
-https://github.com/thekiwismarthome/shopping-list-manager
+| Component | Minimum Version |
-
+|---|---|
-Repository type: **Integration**
+| Home Assistant | 2024.1 |
+| HACS | 2.x |
 
 ---
 
-## 2. Manual Installation (Optional)
+## Installation
 
-1. Copy the folder:
+### Via HACS (Recommended)
-custom_components/shopping_list_manager
 
-2. Paste it into:
+[![Open your Home Assistant instance and open this repository inside the Home Assistant Community Store.](https://my.home-assistant.io/badges/hacs_repository.svg)](https://my.home-assistant.io/redirect/hacs_repository/?owner=thekiwismarthome&repository=shopping-list-manager&category=integration)
-/config/custom_components/
 
-3. Restart Home Assistant.
+1. Click the button above
+2. Confirm adding the repository to HACS
+3. Install **Shopping List Manager** from **HACS → Integrations**
+4. Restart Home Assistant
+5. Go to **Settings → Devices & Services → Add Integration** and search for **Shopping List Manager**
+
+### Manual Installation
+
+1. Copy the `custom_components/shopping_list_manager/` folder into your HA `/config/custom_components/` directory
+2. Restart Home Assistant
+3. Go to **Settings → Devices & Services → Add Integration** and search for **Shopping List Manager**
+
+---
+
+## Lovelace Card
+
+Install the companion card to get the full shopping UI:
 
-## 3. Shopping List Card to go with this Integration
 [![Open your Home Assistant instance and open this repository inside the Home Assistant Community Store.](https://my.home-assistant.io/badges/hacs_repository.svg)](https://my.home-assistant.io/redirect/hacs_repository/?owner=thekiwismarthome&repository=shopping-list-manager-card&category=plugin)
+
+---
+
+## Documentation
+
+Full documentation is available in the [Wiki](https://github.com/thekiwismarthome/shopping-list-manager/wiki).
+
+## Support & Feedback
+
+- [Open an Issue](https://github.com/thekiwismarthome/shopping-list-manager/issues)
+- [Home Assistant Community Forum](https://community.home-assistant.io)
+
+---
+
+## License
+
+MIT — see [LICENSE](LICENSE) for details.