Fix avatar and display name update issues

- Remove avatar handling from profile update to prevent overwriting DB with display URL
- Skip ensureParent for .avatars to speed up upload
- Add change detection for display name save button
- Update API client to not send avatarUrl in profile update

go_cloud/internal/storage/webdav.go

@@ -91,9 +91,11 @@ func (c *WebDAVClient) Upload(ctx context.Context, remotePath string, r io.Reade
 	if c == nil {
 		return fmt.Errorf("no webdav client configured")
 	}
-	// Ensure parent collections
-	if err := c.ensureParent(ctx, remotePath); err != nil {
-		return err
+	// Ensure parent collections, skip for .avatars as it should exist
+	if !strings.HasPrefix(remotePath, ".avatars/") {
+		if err := c.ensureParent(ctx, remotePath); err != nil {
+			return err
+		}
 	}
 	// Construct URL
 	// remotePath might be like /orgs/<id>/file.txt; ensure it joins to basePrefix