feat(public): implement chatwoot public inbox flow

internal/repository/inbox_repo.go

@@ -7,6 +7,7 @@ import (
 	"gorm.io/gorm"
 
 	"github.com/gochat/gochat/internal/model"
+	channelmodel "github.com/gochat/gochat/internal/model/channel"
 )
 
 // InboxRepo implements GORM repository for Inbox.
@@ -145,6 +146,19 @@ func (r *InboxRepo) FindByWebsiteToken(ctx context.Context, websiteToken string)
 	return nil, gorm.ErrRecordNotFound
 }
 
+// FindAPIInboxByIdentifier resolves a public API inbox via Channel::Api identifier.
+func (r *InboxRepo) FindAPIInboxByIdentifier(ctx context.Context, identifier string) (*model.Inbox, *channelmodel.ChannelAPI, error) {
+	var channelAPI channelmodel.ChannelAPI
+	if err := r.db.WithContext(ctx).Where("identifier = ?", identifier).First(&channelAPI).Error; err != nil {
+		return nil, nil, err
+	}
+	inbox, err := r.FindByID(ctx, channelAPI.InboxID)
+	if err != nil {
+		return nil, nil, err
+	}
+	return inbox, &channelAPI, nil
+}
+
 // parseChannelConfig parses the JSON-encoded ChannelConfig string into a map.
 func parseChannelConfig(inbox *model.Inbox) map[string]interface{} {
 	if inbox.ChannelConfig == "" {
@@ -176,4 +190,4 @@ func (r *InboxRepo) UpdateSecret(ctx context.Context, id uint, secret string) er
 func (r *InboxRepo) UpdateFields(ctx context.Context, id uint, updates map[string]interface{}) error {
 	return r.db.WithContext(ctx).Model(&model.Inbox{}).Where("id = ?", id).
 		Updates(updates).Error
-}
+}