docs: enhance documentation with comprehensive API, architecture, and installation guides

- Add detailed API documentation for core functions, SSE, and WebSocket APIs
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- Improve troubleshooting documentation with advanced debugging techniques
- Update site navigation and markdown configuration

docs/api/core.md

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+---
+layout: default
+title: Core Functions
+parent: API Reference
+nav_order: 3
+---
+
+# Core Functions API 🔧
+
+The Core Functions API provides the fundamental operations for interacting with Home Assistant devices and services through MCP Server.
+
+## Device Control
+
+### Get Device State
+
+Retrieve the current state of devices.
+
+```http
+GET /api/state
+GET /api/state/{entity_id}
+```
+
+Parameters:
+- `entity_id` (optional): Specific device ID to query
+
+```bash
+# Get all states
+curl http://localhost:3000/api/state
+
+# Get specific device state
+curl http://localhost:3000/api/state/light.living_room
+```
+
+Response:
+```json
+{
+  "entity_id": "light.living_room",
+  "state": "on",
+  "attributes": {
+    "brightness": 255,
+    "color_temp": 370,
+    "friendly_name": "Living Room Light"
+  },
+  "last_changed": "2024-01-20T15:30:00Z"
+}
+```
+
+### Control Device
+
+Execute device commands.
+
+```http
+POST /api/device/control
+```
+
+Request body:
+```json
+{
+  "entity_id": "light.living_room",
+  "action": "turn_on",
+  "parameters": {
+    "brightness": 200,
+    "color_temp": 400
+  }
+}
+```
+
+Available actions:
+- `turn_on`
+- `turn_off`
+- `toggle`
+- `set_value`
+
+Example with curl:
+```bash
+curl -X POST http://localhost:3000/api/device/control \
+  -H "Content-Type: application/json" \
+  -H "Authorization: Bearer YOUR_JWT_TOKEN" \
+  -d '{
+    "entity_id": "light.living_room",
+    "action": "turn_on",
+    "parameters": {
+      "brightness": 200
+    }
+  }'
+```
+
+## Natural Language Commands
+
+### Execute Command
+
+Process natural language commands.
+
+```http
+POST /api/command
+```
+
+Request body:
+```json
+{
+  "command": "Turn on the living room lights and set them to 50% brightness"
+}
+```
+
+Example usage:
+```bash
+curl -X POST http://localhost:3000/api/command \
+  -H "Content-Type: application/json" \
+  -H "Authorization: Bearer YOUR_JWT_TOKEN" \
+  -d '{
+    "command": "Turn on the living room lights and set them to 50% brightness"
+  }'
+```
+
+Response:
+```json
+{
+  "success": true,
+  "actions": [
+    {
+      "entity_id": "light.living_room",
+      "action": "turn_on",
+      "parameters": {
+        "brightness": 127
+      },
+      "status": "completed"
+    }
+  ],
+  "message": "Command executed successfully"
+}
+```
+
+## Scene Management
+
+### Create Scene
+
+Define a new scene with multiple actions.
+
+```http
+POST /api/scene
+```
+
+Request body:
+```json
+{
+  "name": "Movie Night",
+  "description": "Perfect lighting for movie watching",
+  "actions": [
+    {
+      "entity_id": "light.living_room",
+      "action": "turn_on",
+      "parameters": {
+        "brightness": 50,
+        "color_temp": 500
+      }
+    },
+    {
+      "entity_id": "cover.living_room",
+      "action": "close"
+    }
+  ]
+}
+```
+
+### Activate Scene
+
+Trigger a predefined scene.
+
+```http
+POST /api/scene/{scene_name}/activate
+```
+
+Example:
+```bash
+curl -X POST http://localhost:3000/api/scene/movie_night/activate \
+  -H "Authorization: Bearer YOUR_JWT_TOKEN"
+```
+
+## Groups
+
+### Create Device Group
+
+Create a group of devices for collective control.
+
+```http
+POST /api/group
+```
+
+Request body:
+```json
+{
+  "name": "Living Room",
+  "entities": [
+    "light.living_room_main",
+    "light.living_room_accent",
+    "switch.living_room_fan"
+  ]
+}
+```
+
+### Control Group
+
+Control multiple devices in a group.
+
+```http
+POST /api/group/{group_name}/control
+```
+
+Request body:
+```json
+{
+  "action": "turn_off"
+}
+```
+
+## System Operations
+
+### Health Check
+
+Check server status and connectivity.
+
+```http
+GET /health
+```
+
+Response:
+```json
+{
+  "status": "healthy",
+  "version": "1.0.0",
+  "uptime": 3600,
+  "homeAssistant": {
+    "connected": true,
+    "version": "2024.1.0"
+  }
+}
+```
+
+### Configuration
+
+Get current server configuration.
+
+```http
+GET /api/config
+```
+
+Response:
+```json
+{
+  "server": {
+    "port": 3000,
+    "host": "0.0.0.0",
+    "version": "1.0.0"
+  },
+  "homeAssistant": {
+    "url": "http://homeassistant:8123",
+    "connected": true
+  },
+  "features": {
+    "nlp": true,
+    "scenes": true,
+    "groups": true
+  }
+}
+```
+
+## Error Handling
+
+All endpoints follow standard HTTP status codes and return detailed error messages:
+
+```json
+{
+  "error": true,
+  "code": "INVALID_ENTITY",
+  "message": "Device 'light.nonexistent' not found",
+  "details": {
+    "entity_id": "light.nonexistent",
+    "available_entities": [
+      "light.living_room",
+      "light.kitchen"
+    ]
+  }
+}
+```
+
+Common error codes:
+- `INVALID_ENTITY`: Device not found
+- `INVALID_ACTION`: Unsupported action
+- `INVALID_PARAMETERS`: Invalid command parameters
+- `AUTHENTICATION_ERROR`: Invalid or missing token
+- `CONNECTION_ERROR`: Home Assistant connection issue
+
+## TypeScript Interfaces
+
+```typescript
+interface DeviceState {
+  entity_id: string;
+  state: string;
+  attributes: Record<string, any>;
+  last_changed: string;
+}
+
+interface DeviceCommand {
+  entity_id: string;
+  action: 'turn_on' | 'turn_off' | 'toggle' | 'set_value';
+  parameters?: Record<string, any>;
+}
+
+interface Scene {
+  name: string;
+  description?: string;
+  actions: DeviceCommand[];
+}
+
+interface Group {
+  name: string;
+  entities: string[];
+}
+```
+
+## Related Resources
+
+- [API Overview](index.md)
+- [SSE API](sse.md)
+- [Architecture](../architecture.md)
+- [Examples](https://github.com/jango-blockchained/advanced-homeassistant-mcp/tree/main/examples)