Align backend with frontend, make clips end-to-end, polish admin

Backend
- Add ClipSubmission entity + table (runtime bootstrapper) and
  POST /api/public/clips (server-derives platform from the link)
- Surface clip submissions in the admin season detail
- Add DELETE candidate/category/clip endpoints with audit entries

Frontend
- Clips admin: real moderation view (list, open link, delete) instead
  of placeholder; wired clipSubmissions through types/api/store
- Categories admin: add delete with confirm modal (matches Candidates)
- Voting ranking bar uses the unified purple gradient
- Fix ASCII transliterations to proper German umlauts across admin
- Remove orphan AdminView 2.vue

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

Backend/Program.cs

@@ -621,6 +621,70 @@ app.MapPost("/api/public/votes", async (HttpContext context, CreateVoteRequest r
 .WithName("CreateVote")
 .WithOpenApi();
 
+app.MapPost("/api/public/clips", async (HttpContext context, CreateClipRequest request, AwardsDbContext db) =>
+{
+    var clipUrl = request.ClipUrl?.Trim() ?? string.Empty;
+    if (string.IsNullOrWhiteSpace(clipUrl))
+    {
+        return Results.BadRequest(new { message = "A clip link is required." });
+    }
+
+    var loweredUrl = clipUrl.ToLowerInvariant();
+    var platform = loweredUrl.Contains("twitch.tv")
+        ? "Twitch"
+        : loweredUrl.Contains("youtube.com") || loweredUrl.Contains("youtu.be")
+            ? "YouTube"
+            : "Other";
+
+    if (platform == "Other")
+    {
+        return Results.BadRequest(new { message = "Only Twitch or YouTube clip links are supported." });
+    }
+
+    var season = await db.Seasons.FirstOrDefaultAsync(item => item.Year == request.Year);
+    if (season is null)
+    {
+        return Results.BadRequest(new { message = "The selected season does not exist." });
+    }
+
+    if (request.CategoryId is int categoryId)
+    {
+        var categoryExists = await db.Categories.AnyAsync(item => item.Id == categoryId && item.SeasonId == season.Id);
+        if (!categoryExists)
+        {
+            return Results.BadRequest(new { message = "The selected category does not exist for this season." });
+        }
+    }
+
+    var session = await ResolveSessionAsync(context, db);
+    var submitterId = session?.TwitchUserId ?? request.TwitchUserId;
+    if (string.IsNullOrWhiteSpace(submitterId))
+    {
+        return Results.BadRequest(new { message = "A logged in user is required to submit clips." });
+    }
+
+    var clip = new ClipSubmission
+    {
+        SeasonId = season.Id,
+        CategoryId = request.CategoryId,
+        SubmittedByTwitchId = submitterId,
+        ClipUrl = clipUrl,
+        Title = request.Title?.Trim() ?? string.Empty,
+        Creator = request.Creator?.Trim() ?? string.Empty,
+        Platform = platform,
+        Status = "pending",
+        CreatedFromIp = ReadClientIp(context),
+        CreatedAt = DateTimeOffset.UtcNow,
+    };
+
+    db.ClipSubmissions.Add(clip);
+    await db.SaveChangesAsync();
+
+    return Results.Ok(new { saved = true, clipId = clip.Id });
+})
+.WithName("CreateClip")
+.WithOpenApi();
+
 app.MapGet("/api/admin/dashboard", async (HttpContext context, AwardsDbContext db) =>
 {
     var session = await ResolveSessionAsync(context, db);
@@ -809,6 +873,23 @@ app.MapGet("/api/admin/seasons/{seasonId:int}", async (HttpContext context, int
             item.CreatedAt))
         .ToArrayAsync();
 
+    var clipSubmissions = await db.ClipSubmissions
+        .AsNoTracking()
+        .Where(item => item.SeasonId == seasonId)
+        .OrderByDescending(item => item.CreatedAt)
+        .Take(100)
+        .Select(item => new AdminClipSubmissionItemDto(
+            item.Id,
+            item.CategoryId,
+            item.SubmittedByTwitchId,
+            item.ClipUrl,
+            item.Title,
+            item.Creator,
+            item.Platform,
+            item.Status,
+            item.CreatedAt))
+        .ToArrayAsync();
+
     return Results.Ok(new AdminSeasonDetailResponse(
         season.Id,
         season.Year,
@@ -817,7 +898,8 @@ app.MapGet("/api/admin/seasons/{seasonId:int}", async (HttpContext context, int
         season.IsCurrent,
         categories,
         candidates,
-        pendingNominations));
+        pendingNominations,
+        clipSubmissions));
 })
 .WithName("GetAdminSeasonDetail")
 .WithOpenApi();
@@ -1013,6 +1095,102 @@ app.MapPut("/api/admin/candidates/{candidateId:int}", async (HttpContext context
 .WithName("UpdateAdminCandidate")
 .WithOpenApi();
 
+app.MapDelete("/api/admin/candidates/{candidateId:int}", async (HttpContext context, int candidateId, AwardsDbContext db) =>
+{
+    var session = await ResolveSessionAsync(context, db);
+    if (session?.Role != "admin")
+    {
+        return Results.Unauthorized();
+    }
+
+    var candidate = await db.Candidates.FirstOrDefaultAsync(item => item.Id == candidateId);
+    if (candidate is null)
+    {
+        return Results.NotFound();
+    }
+
+    db.Candidates.Remove(candidate);
+    AddAuditEntry(
+        db,
+        session.TwitchUserId,
+        "candidate.delete",
+        "candidate",
+        candidate.Id.ToString(),
+        $"Kandidat {candidate.DisplayName} wurde gelöscht.",
+        new { candidate.CategoryId, candidate.Platform });
+    await db.SaveChangesAsync();
+
+    return Results.Ok(new { deleted = true, candidateId });
+})
+.WithName("DeleteAdminCandidate")
+.WithOpenApi();
+
+app.MapDelete("/api/admin/categories/{categoryId:int}", async (HttpContext context, int categoryId, AwardsDbContext db) =>
+{
+    var session = await ResolveSessionAsync(context, db);
+    if (session?.Role != "admin")
+    {
+        return Results.Unauthorized();
+    }
+
+    var category = await db.Categories.FirstOrDefaultAsync(item => item.Id == categoryId);
+    if (category is null)
+    {
+        return Results.NotFound();
+    }
+
+    var candidates = await db.Candidates.Where(item => item.CategoryId == categoryId).ToArrayAsync();
+    if (candidates.Length > 0)
+    {
+        db.Candidates.RemoveRange(candidates);
+    }
+
+    db.Categories.Remove(category);
+    AddAuditEntry(
+        db,
+        session.TwitchUserId,
+        "category.delete",
+        "category",
+        category.Id.ToString(),
+        $"Kategorie {category.Name} wurde gelöscht.",
+        new { removedCandidates = candidates.Length });
+    await db.SaveChangesAsync();
+
+    return Results.Ok(new { deleted = true, categoryId });
+})
+.WithName("DeleteAdminCategory")
+.WithOpenApi();
+
+app.MapDelete("/api/admin/clips/{clipId:int}", async (HttpContext context, int clipId, AwardsDbContext db) =>
+{
+    var session = await ResolveSessionAsync(context, db);
+    if (session?.Role != "admin")
+    {
+        return Results.Unauthorized();
+    }
+
+    var clip = await db.ClipSubmissions.FirstOrDefaultAsync(item => item.Id == clipId);
+    if (clip is null)
+    {
+        return Results.NotFound();
+    }
+
+    db.ClipSubmissions.Remove(clip);
+    AddAuditEntry(
+        db,
+        session.TwitchUserId,
+        "clip.delete",
+        "clip",
+        clip.Id.ToString(),
+        $"Clip-Einreichung von {clip.SubmittedByTwitchId} wurde entfernt.",
+        new { clip.Platform });
+    await db.SaveChangesAsync();
+
+    return Results.Ok(new { deleted = true, clipId });
+})
+.WithName("DeleteAdminClip")
+.WithOpenApi();
+
 app.MapPost("/api/admin/nominations/{nominationId:int}/approve", async (HttpContext context, int nominationId, ApproveNominationRequest request, AwardsDbContext db) =>
 {
     var session = await ResolveSessionAsync(context, db);