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/Contracts/AdminSiteSettingsContracts.cs

@@ -4,6 +4,8 @@ public sealed record AdminSiteSettingsResponse(
     string HostDisplayName,
     string HostTagline,
     string NewsletterUrl,
+    string ShareXUrl,
+    string ShareDiscordUrl,
     string PrivacyEmail,
     string PrivacyPolicyContent,
     string? PrivacyPolicyUpdatedBy,
@@ -17,12 +19,15 @@ public sealed record AdminSiteSettingsResponse(
     string ShowactsUrl,
     string ShowactsContent,
     IEnumerable<PublicSocialLinkDto> SocialLinks,
-    IEnumerable<FaqItemDto> Faq);
+    IEnumerable<FaqItemDto> Faq,
+    string ShowactFormSchemaJson);
 
 public sealed record UpdateSiteSettingsRequest(
     string HostDisplayName,
     string HostTagline,
     string NewsletterUrl,
+    string ShareXUrl,
+    string ShareDiscordUrl,
     string PrivacyEmail,
     string PrivacyPolicyContent,
     string ImprintUrl,
@@ -34,7 +39,8 @@ public sealed record UpdateSiteSettingsRequest(
     string ShowactsUrl,
     string ShowactsContent,
     PublicSocialLinkDto[] SocialLinks,
-    FaqItemDto[] Faq);
+    FaqItemDto[] Faq,
+    string? ShowactFormSchemaJson = null);
 
 public sealed record AdminOperationalSettingsResponse(
     bool DemoLoginManagedByDatabase,
@@ -49,6 +55,7 @@ public sealed record AdminOperationalSettingsResponse(
     bool TwitchClientSecretSet,
     string TwitchRedirectUri,
     string TwitchScope,
+    int SessionIdleTimeoutHours,
     bool MaintenanceModeEnabled,
     string MaintenanceTitle,
     string MaintenanceMessage);
@@ -59,6 +66,9 @@ public sealed record AdminOptionalFeatureSettingsResponse(
     bool ClipAdminMenuVisible,
     string ClipSubmissionDisabledMessage,
     bool ShowactApplicationsEnabled,
+    DateOnly? ShowactApplicationStartsAt,
+    DateOnly? ShowactApplicationEndsAt,
+    bool ShowactApplicationsOpenNow,
     string ShowactApplicationDisabledMessage,
     bool SponsorsVisible);
 
@@ -68,6 +78,8 @@ public sealed record UpdateOptionalFeatureSettingsRequest(
     bool ClipAdminMenuVisible,
     string ClipSubmissionDisabledMessage,
     bool ShowactApplicationsEnabled,
+    DateOnly? ShowactApplicationStartsAt,
+    DateOnly? ShowactApplicationEndsAt,
     string ShowactApplicationDisabledMessage,
     bool SponsorsVisible);
 
@@ -81,6 +93,71 @@ public sealed record UpdateOperationalSettingsRequest(
     string? TwitchClientSecret,
     string TwitchRedirectUri,
     string TwitchScope,
+    int SessionIdleTimeoutHours,
     bool MaintenanceModeEnabled,
     string MaintenanceTitle,
     string MaintenanceMessage);
+
+public sealed record AdminTrackingSourceDto(
+    string ProviderKey,
+    string ProviderLabel,
+    string BaseUrl,
+    string NotesSummary,
+    bool ShowManualReviewNotesInReview);
+
+public sealed record AdminTrackingMetricRuleDto(
+    string Key,
+    string Label,
+    bool Enabled,
+    string SourceSupport,
+    string Description,
+    bool RequiredForAutoClassification,
+    bool ShowInReview,
+    bool ShowInAdminSummary,
+    bool ManualOverrideAllowed,
+    string WindowKey,
+    string[] AutoSupportedWindowKeys,
+    string? ProviderFieldKey,
+    int? TopCount,
+    int? MinPrimaryCategorySharePercent,
+    int? MinPrimaryCategoryHours,
+    int? MaxDistinctCategoriesBeforeFlag,
+    string[] IgnoredCategories,
+    bool MatchAwardCategoryAgainstTopCategories,
+    bool FlagIfAwardCategoryNotInTopX,
+    bool FlagIfCategorySpreadTooWide,
+    bool FlagIfNoCategoryContextAvailable,
+    int? MinValue,
+    int? MaxValue);
+
+public sealed record AdminTrackingFlagRuleDto(
+    string Key,
+    string Label,
+    bool Enabled,
+    string Severity,
+    string Description,
+    bool AutoTriggerEnabled,
+    bool RequiresManualReview,
+    bool BlocksApproval,
+    bool AdminNoteRequiredOnOverride);
+
+public sealed record AdminTrackingRulesResponse(
+    AdminTrackingSourceDto Source,
+    AdminTrackingMetricRuleDto[] ImportantMetrics,
+    AdminTrackingMetricRuleDto[] OptionalMetrics,
+    AdminTrackingFlagRuleDto[] Flags,
+    string ManualReviewNotes);
+
+public sealed record UpdateTrackingRulesRequest(
+    AdminTrackingSourceDto Source,
+    AdminTrackingMetricRuleDto[] ImportantMetrics,
+    AdminTrackingMetricRuleDto[] OptionalMetrics,
+    AdminTrackingFlagRuleDto[] Flags,
+    string ManualReviewNotes);
+
+public sealed record UpdateTrackingSourceRequest(
+    AdminTrackingSourceDto Source);
+
+public sealed record UpdateTrackingReviewNotesRequest(
+    string ManualReviewNotes,
+    bool ShowManualReviewNotesInReview);