feat(channels): align whatsapp authorization

internal/handler/api/v1/inbox_handler.go

@@ -153,6 +153,44 @@ func (h *InboxHandler) Create(c *gin.Context) {
 	c.JSON(http.StatusOK, serializeInbox(inbox))
 }
 
+// WhatsAppAuthorization handles Chatwoot's embedded signup callback for
+// WhatsApp Cloud channel creation and reauthorization.
+// POST /api/v1/accounts/:account_id/whatsapp/authorization
+func (h *InboxHandler) WhatsAppAuthorization(c *gin.Context) {
+	accountID, err := parseUintParam(c, "account_id")
+	if err != nil {
+		response.AbortWithStatusError(c, http.StatusBadRequest, response.ErrBadRequest, "invalid account_id")
+		return
+	}
+
+	var req service.WhatsAppAuthorizationRequest
+	if err := c.ShouldBind(&req); err != nil {
+		c.JSON(http.StatusUnprocessableEntity, gin.H{"success": false, "error": err.Error()})
+		return
+	}
+
+	result, svcErr := h.svc.AuthorizeWhatsAppEmbeddedSignup(c.Request.Context(), accountID, req)
+	if svcErr != nil {
+		status := http.StatusUnprocessableEntity
+		if req.InboxID != nil && strings.Contains(strings.ToLower(svcErr.Error()), "record not found") {
+			status = http.StatusNotFound
+		}
+		c.JSON(status, gin.H{"success": false, "error": svcErr.Error()})
+		return
+	}
+
+	payload := gin.H{
+		"success":      true,
+		"id":           result.Inbox.ID,
+		"name":         result.Inbox.Name,
+		"channel_type": "whatsapp",
+	}
+	if result.Message != "" {
+		payload["message"] = result.Message
+	}
+	c.JSON(http.StatusOK, payload)
+}
+
 // @Summary Update an inbox
 // @Description Updates an existing inbox's configuration
 // @Tags Inboxes