feat(ui): add message cache management page and dashboard enhancements

- Introduced MessageCachePage for browsing and managing cached webhook events.
- Enhanced DashboardPage to display runtime stats and message cache information.
- Added new API types for message cache events and system stats.
- Integrated SwaggerPage for API documentation and live request testing.

pkg/config/config.go

@@ -62,7 +62,7 @@ type WhatsAppConfig struct {
 type BusinessAPIConfig struct {
 	PhoneNumberID     string `json:"phone_number_id"`
 	AccessToken       string `json:"access_token"`
-	WABAId            string `json:"waba_id,omitempty"`            // WhatsApp Business Account ID (resolved at connect time)
+	WABAId            string `json:"waba_id,omitempty"`             // WhatsApp Business Account ID (resolved at connect time)
 	BusinessAccountID string `json:"business_account_id,omitempty"` // Facebook Business Manager ID (optional)
 	APIVersion        string `json:"api_version,omitempty"`         // Default: v21.0
 	WebhookPath       string `json:"webhook_path,omitempty"`
@@ -131,6 +131,7 @@ type MQTTConfig struct {
 // MessageCacheConfig holds message cache configuration
 type MessageCacheConfig struct {
 	Enabled    bool   `json:"enabled"`                // Enable message caching
+	Storage    string `json:"storage,omitempty"`      // Storage backend: "database" (default) or "disk"
 	DataPath   string `json:"data_path,omitempty"`    // Directory to store cached events
 	MaxAgeDays int    `json:"max_age_days,omitempty"` // Maximum age in days before purging (default: 7)
 	MaxEvents  int    `json:"max_events,omitempty"`   // Maximum number of events to cache (default: 10000)
@@ -207,6 +208,9 @@ func Load(path string) (*Config, error) {
 	}
 
 	// Set message cache defaults
+	if cfg.MessageCache.Storage == "" {
+		cfg.MessageCache.Storage = "database"
+	}
 	if cfg.MessageCache.DataPath == "" {
 		cfg.MessageCache.DataPath = "./data/message_cache"
 	}