feat: persistent config

docs/Architecture.md

@@ -291,6 +291,51 @@ The system includes automatic WiFi fallback for robust operation:
 
 ## Configuration Management
 
+SPORE implements a persistent configuration system that manages device settings across reboots and provides runtime reconfiguration capabilities.
+
+### Configuration Architecture
+
+The configuration system consists of several key components:
+
+- **`Config` Class**: Central configuration management with default constants
+- **LittleFS Storage**: Persistent file-based storage (`/config.json`)
+- **Runtime Updates**: Live configuration changes via HTTP API
+- **Automatic Persistence**: Configuration changes are automatically saved
+
+### Configuration Categories
+
+| Category | Description | Examples |
+|----------|-------------|----------|
+| **WiFi Configuration** | Network connection settings | SSID, password, timeouts |
+| **Network Configuration** | Network service settings | UDP port, API server port |
+| **Cluster Configuration** | Cluster management settings | Discovery intervals, heartbeat timing |
+| **Node Status Thresholds** | Health monitoring thresholds | Active/inactive/dead timeouts |
+| **System Configuration** | Core system settings | Restart delay, JSON document size |
+| **Memory Management** | Resource management settings | Memory thresholds, HTTP request limits |
+
+### Configuration Lifecycle
+
+1. **Boot Process**: Load configuration from `/config.json` or use defaults
+2. **Runtime Updates**: Configuration changes via HTTP API
+3. **Persistent Storage**: Changes automatically saved to LittleFS
+4. **Service Integration**: Configuration applied to all system services
+
+### Default Value Management
+
+All default values are defined as `constexpr` constants in the `Config` class:
+
+```cpp
+static constexpr const char* DEFAULT_WIFI_SSID = "shroud";
+static constexpr uint16_t DEFAULT_UDP_PORT = 4210;
+static constexpr unsigned long DEFAULT_HEARTBEAT_INTERVAL_MS = 5000;
+```
+
+This ensures:
+- **Single Source of Truth**: All defaults defined once
+- **Type Safety**: Compile-time type checking
+- **Maintainability**: Easy to update default values
+- **Consistency**: Same defaults used in `setDefaults()` and `loadFromFile()`
+
 ### Environment Variables
 
 ```bash
@@ -380,6 +425,8 @@ pio device monitor
 
 ## Related Documentation
 
+- **[Configuration Management](./ConfigurationManagement.md)** - Persistent configuration system
+- **[WiFi Configuration](./WiFiConfiguration.md)** - WiFi setup and reconfiguration process
 - **[Task Management](./TaskManagement.md)** - Background task system
 - **[API Reference](./API.md)** - REST API documentation
 - **[TaskManager API](./TaskManager.md)** - TaskManager class reference