[MM-29049] Fix remaining errcheck errors in app, api4 and web package (#31307)

Co-authored-by: Claude <noreply@anthropic.com>

server/channels/api4/cloud.go

@@ -80,7 +80,9 @@ func getPreviewSubscription(c *Context, w http.ResponseWriter, r *http.Request)
 		return
 	}
 
-	w.Write(json)
+	if _, err := w.Write(json); err != nil {
+		c.Logger.Warn("Error while writing response", mlog.Err(err))
+	}
 }
 
 func getSubscription(c *Context, w http.ResponseWriter, r *http.Request) {
@@ -143,7 +145,9 @@ func getSubscription(c *Context, w http.ResponseWriter, r *http.Request) {
 		return
 	}
 
-	w.Write(json)
+	if _, err := w.Write(json); err != nil {
+		c.Logger.Warn("Error while writing response", mlog.Err(err))
+	}
 }
 
 func validateBusinessEmail(c *Context, w http.ResponseWriter, r *http.Request) {
@@ -276,11 +280,15 @@ func getCloudProducts(c *Context, w http.ResponseWriter, r *http.Request) {
 			return
 		}
 
-		w.Write(byteSanitizedProductsData)
+		if _, err := w.Write(byteSanitizedProductsData); err != nil {
+			c.Logger.Warn("Error while writing response", mlog.Err(err))
+		}
 		return
 	}
 
-	w.Write(byteProductsData)
+	if _, err := w.Write(byteProductsData); err != nil {
+		c.Logger.Warn("Error while writing response", mlog.Err(err))
+	}
 }
 
 func getCloudLimits(c *Context, w http.ResponseWriter, r *http.Request) {
@@ -306,7 +314,9 @@ func getCloudLimits(c *Context, w http.ResponseWriter, r *http.Request) {
 		return
 	}
 
-	w.Write(json)
+	if _, err := w.Write(json); err != nil {
+		c.Logger.Warn("Error while writing response", mlog.Err(err))
+	}
 }
 
 func getCloudCustomer(c *Context, w http.ResponseWriter, r *http.Request) {
@@ -337,7 +347,9 @@ func getCloudCustomer(c *Context, w http.ResponseWriter, r *http.Request) {
 		return
 	}
 
-	w.Write(json)
+	if _, err := w.Write(json); err != nil {
+		c.Logger.Warn("Error while writing response", mlog.Err(err))
+	}
 }
 
 func getInstallation(c *Context, w http.ResponseWriter, r *http.Request) {
@@ -403,7 +415,9 @@ func updateCloudCustomer(c *Context, w http.ResponseWriter, r *http.Request) {
 		return
 	}
 
-	w.Write(json)
+	if _, err := w.Write(json); err != nil {
+		c.Logger.Warn("Error while writing response", mlog.Err(err))
+	}
 }
 
 func updateCloudCustomerAddress(c *Context, w http.ResponseWriter, r *http.Request) {
@@ -446,7 +460,9 @@ func updateCloudCustomerAddress(c *Context, w http.ResponseWriter, r *http.Reque
 		return
 	}
 
-	w.Write(json)
+	if _, err := w.Write(json); err != nil {
+		c.Logger.Warn("Error while writing response", mlog.Err(err))
+	}
 }
 
 func getInvoicesForSubscription(c *Context, w http.ResponseWriter, r *http.Request) {
@@ -477,7 +493,9 @@ func getInvoicesForSubscription(c *Context, w http.ResponseWriter, r *http.Reque
 		return
 	}
 
-	w.Write(json)
+	if _, err := w.Write(json); err != nil {
+		c.Logger.Warn("Error while writing response", mlog.Err(err))
+	}
 }
 
 func getSubscriptionInvoicePDF(c *Context, w http.ResponseWriter, r *http.Request) {