Add challenges background preference support: Extend site preferences and related components to include challengesBackground, update API and UI to handle new background image settings for challenges.

prisma/migrations/20251215202319_add_challenges_background/migration.sql

@@ -0,0 +1,17 @@
+-- RedefineTables
+PRAGMA defer_foreign_keys=ON;
+PRAGMA foreign_keys=OFF;
+CREATE TABLE "new_SitePreferences" (
+    "id" TEXT NOT NULL PRIMARY KEY DEFAULT 'global',
+    "homeBackground" TEXT,
+    "eventsBackground" TEXT,
+    "leaderboardBackground" TEXT,
+    "challengesBackground" TEXT,
+    "createdAt" DATETIME NOT NULL DEFAULT CURRENT_TIMESTAMP,
+    "updatedAt" DATETIME NOT NULL
+);
+INSERT INTO "new_SitePreferences" ("createdAt", "eventsBackground", "homeBackground", "id", "leaderboardBackground", "updatedAt") SELECT "createdAt", "eventsBackground", "homeBackground", "id", "leaderboardBackground", "updatedAt" FROM "SitePreferences";
+DROP TABLE "SitePreferences";
+ALTER TABLE "new_SitePreferences" RENAME TO "SitePreferences";
+PRAGMA foreign_keys=ON;
+PRAGMA defer_foreign_keys=OFF;