Add viewer-range categories, nomination tracking, dynamic showact form, session timeout, share URLs, and workflow-per-season

Features:
- Category viewer ranges + subcategory templates (admin group modal, tree workspace)
- Nomination enrichment via TwitchTracker API (NominationEnrichmentService,
  TwitchTrackerViewerStatsProvider) with admin tracking rules editor
- Nomination group tracker: CategoryGroupName as primary identifier,
  CategoryId stays as nullable legacy field; StreamerIdentity table
- Dynamic showact application form builder (AdminShowactFormBuilder,
  ShowactApplicationSchedule)
- Session idle timeout setting (AdminSessionTimeoutCard)
- Share URLs for X and Discord (SiteSettings, public extras)
- Workflow rules now stored per season (falls back to global SiteSettings)
- New admin routes: settings/access, settings/workflows, tracking-rules
- New admin review workspace with subcategory tabs
- AdminCategoriesView rebuilt with group/subcategory modals

Migrations (all additive):
- AddShareUrls, AddShowactDynamicForm, AddCategoryViewerRanges,
  AddSessionIdleTimeoutSettings, AddSeasonSubcategoryTemplates,
  AddNominationGroupTrackerIdentity, AddShowactApplicationSchedule,
  AddSeasonWorkflowRulesJson

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

Backend/Endpoints/AdminSeasonResultsEndpoints.cs

@@ -36,7 +36,7 @@ public static partial class AdminSeasonManagementEndpoints
             return Results.BadRequest(new { message = "The selected candidate does not belong to the selected category." });
         }
 
-        var workflowRules = await LoadWorkflowRulesAsync(db, context.RequestAborted);
+        var workflowRules = await LoadWorkflowRulesAsync(db, seasonId, context.RequestAborted);
         var winnerRequiresClipRule = WorkflowRuleSettings.Find(workflowRules, WorkflowRuleSettings.WinnerRequiresClip);
         if (WorkflowRuleSettings.ShouldBlock(winnerRequiresClipRule)
             && string.IsNullOrWhiteSpace(candidate.ClipCompilationUrl))
@@ -56,11 +56,14 @@ public static partial class AdminSeasonManagementEndpoints
                 .Select(item => new
                 {
                     item.CategoryId,
+                    item.Candidate.StreamerIdentityId,
                     item.Candidate.DisplayName,
                     item.Candidate.ChannelSlug,
                 })
                 .ToArrayAsync(context.RequestAborted);
             var existingWinnerCount = existingWinnerIdentities.Count(item =>
+                candidate.StreamerIdentityId.HasValue && item.StreamerIdentityId == candidate.StreamerIdentityId
+                ||
                 string.Equals(WorkflowRuleSettings.CandidateIdentityKey(item.DisplayName, item.ChannelSlug), candidateIdentityKey, StringComparison.Ordinal));
 
             if (existingWinnerCount >= winnerPlacementsRule.Limit)