feat(inboxes): enforce chatwoot inbox limits

internal/handler/api/v1/google_channel_handler.go

@@ -107,6 +107,13 @@ func (h *GoogleChannelHandler) OAuthCallback(c *gin.Context) {
 	}
 
 	ctx := c.Request.Context()
+	if err := h.inboxSvc.EnsureCanCreateInbox(ctx, uint(accountID)); err != nil {
+		if renderInboxLimitExceeded(c, err) {
+			return
+		}
+		c.JSON(http.StatusUnprocessableEntity, gin.H{"error": "failed to create google inbox"})
+		return
+	}
 
 	// Exchange the code for tokens
 	tokenResult, err := h.goProvider.ExchangeToken(ctx, req.Code, req.RedirectURL)
@@ -146,6 +153,12 @@ func (h *GoogleChannelHandler) OAuthCallback(c *gin.Context) {
 	inbox, err := h.inboxSvc.Create(ctx, uint(accountID), inboxReq)
 	if err != nil {
 		applogger.L().Errorf("Failed to create Google inbox: %v", err)
+		if delErr := h.goService.Delete(ctx, goChannel.ID); delErr != nil {
+			applogger.L().Warnf("Failed to rollback Google channel after inbox creation failure: %v", delErr)
+		}
+		if renderInboxLimitExceeded(c, err) {
+			return
+		}
 		c.JSON(http.StatusUnprocessableEntity, gin.H{"error": "failed to create google inbox"})
 		return
 	}