feat(profile): add full-box card background tab and rendering

Adds a "Cards" tab to the Profile Background picker (BackgroundsView)
that selects a pattern applied to the entire user info card and the
extended profile container, in addition to the existing avatar-pad
background/stand/overlay layers.

- AvatarInfoUser/Utilities: propagate cardBackgroundId from RoomUserData.
- InfoStandWidgetUserView: stateful cardBackgroundId, applied as
  .profile-card-background.card-background-{id} on the outer Column
  with bg-color suppressed when active.
- UserContainerView: same class on the wrapper of the extended profile.
- BackgroundsView: 4th tab "cards" backed by cards.data config
  (falls back to backgrounds.data); sends 4-id message via the
  extended sendBackgroundMessage signature.
- ui-config.example: cards.data dataset (15 entries).
- BackgroundsView.css: 188 .card-background-{N} rules cloned from
  background-{N} (repeat-tiled) plus 15 CSS-pattern overrides for the
  provisional dataset (gradients, stripes, dots, grid, checker).

src/api/room/widgets/AvatarInfoUser.ts

@@ -16,6 +16,7 @@ export class AvatarInfoUser implements IAvatarInfo
 	public backgroundId: number = 0;
     public standId: number = 0;
     public overlayId: number = 0;
+    public cardBackgroundId: number = 0;
     public webID: number = 0;
     public xp: number = 0;
     public userType: number = -1;

src/api/room/widgets/AvatarInfoUtilities.ts

@@ -186,6 +186,7 @@ export class AvatarInfoUtilities
 		userInfo.backgroundId = userData.background;
         userInfo.standId = userData.stand;
         userInfo.overlayId = userData.overlay;
+        userInfo.cardBackgroundId = userData.cardBackground ?? 0;
         userInfo.achievementScore = userData.activityPoints;
         userInfo.webID = userData.webID;
         userInfo.roomIndex = userData.roomIndex;