feat: Display candidate name from CV data instead of filename

- Added CandidateName field to CVCheckDto
- Extract candidate name from ReportJson or ExtractedDataJson
- Dashboard now shows actual candidate name for JSON uploads
- PDF export uses candidate name from report

This fixes the issue where JSON files showed their filename (e.g.,
"CLEAN-001") instead of the actual candidate name from the CV data.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

src/RealCV.Application/DTOs/CVCheckDto.cs

@@ -4,6 +4,7 @@ public sealed record CVCheckDto
 {
     public required Guid Id { get; init; }
     public required string OriginalFileName { get; init; }
+    public string? CandidateName { get; init; }
     public required string Status { get; init; }
     public int? VeracityScore { get; init; }
     public string? ProcessingStage { get; init; }