Improve admin candidate modal UX and add clip menu visibility toggle

- Widen AdminCandidateEditorModal to size lg for better readability
- Rename "Clip-Compilation" section to "Clip / Compilation", update copy to reflect single clips too, drop upload hint and Clip-Plattform field, rename label to "Link"
- Fix NativeSelect dropdown clipping inside overflow-y-auto modals by teleporting the menu to body with fixed positioning, flip-up logic, and dynamic maxHeight capped to viewport
- Add ClipAdminMenuVisible setting (backend domain, contracts, endpoint, migration) with matching frontend types, defaults, form wiring, and toggle in the Clip-Workflow modal — hides the Clips nav item from the admin sidebar when disabled

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

Backend/Endpoints/PublicSeasonCategoryReadEndpoints.cs

@@ -54,17 +54,36 @@ public static partial class PublicEndpoints
                 category.GroupName,
                 category.Description,
                 category.MaxNomineesPerUser,
-                category.Candidates.Select(candidate =>
+                category.Candidates
+                    .Where(candidate => !string.Equals(candidate.AcceptanceStatus, "declined", StringComparison.OrdinalIgnoreCase))
+                    .Select(candidate =>
                 {
                     var clip = ResolveCandidateClip(candidate, clipsByCandidateId, clipsByCreatorKey);
+                    var candidateClipUrl = string.IsNullOrWhiteSpace(candidate.ClipCompilationUrl)
+                        || string.Equals(candidate.ClipEmbedStatus, "blocked", StringComparison.OrdinalIgnoreCase)
+                            ? null
+                            : candidate.ClipCompilationUrl.Trim();
+                    var clipUrl = candidateClipUrl ?? clip?.ClipUrl;
+                    var clipTitle = candidateClipUrl is not null
+                        ? string.IsNullOrWhiteSpace(candidate.ClipCompilationTitle) ? "Highlight-Clip ansehen" : candidate.ClipCompilationTitle.Trim()
+                        : clip?.Title;
+                    var clipPlatform = candidateClipUrl is not null
+                        ? string.IsNullOrWhiteSpace(candidate.ClipCompilationPlatform) ? candidate.Platform : candidate.ClipCompilationPlatform.Trim()
+                        : clip?.Platform;
+                    var clipEmbedStatus = candidateClipUrl is not null
+                        ? candidate.ClipEmbedStatus
+                        : null;
+
                     return new CandidateSummaryDto(
                         candidate.Id,
                         candidate.DisplayName,
                         candidate.ChannelSlug,
+                        SeasonMappings.BuildProfileUrl(candidate.Platform, candidate.ChannelSlug),
                         candidate.Platform,
-                        clip?.ClipUrl,
-                        clip?.Title,
-                        clip?.Platform);
+                        clipUrl,
+                        clipTitle,
+                        clipPlatform,
+                        clipEmbedStatus);
                 }).ToArray()))
                 .ToArray()));
     }