Add winner archive, host image upload and live demo data

Deliver the demo-ready feature set and seed data so the live site can be
presented end to end:

- Winner archive: ArchivedWinner domain, admin CRUD endpoints/view/manager
  and public archive surface, backed by AddArchivedWinners migration.
- Host presentation: host image upload and artist name on SiteSettings with
  public image endpoint and supporting migrations.
- Clip submissions: idempotent table-ensure migration plus current-season
  demo clips for review workflows.
- Demo seed data: sponsors, share links and 2025 archived winners, with a
  guarded RemoveDemoSeasons cleanup; all seeds guard against real data.
- EnsureRuntimeSchemaParity migration to align runtime schema defensively.
- Admin/home UI refinements; remove unused team role permissions modal and
  dead share-quick-links code.

All seed and schema migrations are idempotent (IF NOT EXISTS / ON CONFLICT)
and skip when real season data is present.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

Backend/Endpoints/AdminNominationModerationEndpoints.cs

@@ -28,13 +28,6 @@ public static partial class AdminModerationEndpoints
             return Results.NotFound();
         }
 
-        var trackingFlags = TrackingRulesSettings.ReadFlagHits(nomination.TrackingFlagsJson);
-        if (trackingFlags.Any(flag => flag.BlocksApproval)
-            && !string.Equals(nomination.TrackingReviewStatus, "overridden", StringComparison.OrdinalIgnoreCase))
-        {
-            return Results.BadRequest(new { message = "Tracking Rules blockieren die Freigabe. Bitte setze zuerst einen manuellen Override im Review." });
-        }
-
         var rawDisplayName = FirstNonEmpty(request.DisplayName, nomination.CandidateText, nomination.ResolvedChannel);
 
         if (string.IsNullOrWhiteSpace(rawDisplayName))