feat: add content assets and import persistence

Tiku.Domain/Content/AssetEntities.cs

@@ -0,0 +1,243 @@
+using System.Text.Json;
+using Tiku.Domain.Common;
+
+namespace Tiku.Domain.Content;
+
+public sealed class ContentAsset : AuditableTenantEntity
+{
+    public Guid? RegionId { get; set; }
+    public Guid? SubjectId { get; set; }
+    public Guid? CategoryId { get; set; }
+    public Guid? ContentNodeId { get; set; }
+    public Guid? CreatedBy { get; set; }
+    public Guid? UpdatedBy { get; set; }
+    public Guid? VerifiedBy { get; set; }
+    public string? LegacyId { get; set; }
+    public string? AssetKey { get; set; }
+    public string? Title { get; set; }
+    public string? Category { get; set; }
+    public string? Description { get; set; }
+    public string? FileName { get; set; }
+    public string? CdnUrl { get; set; }
+    public bool IsPublic { get; set; }
+    public ContentAssetType AssetType { get; set; } = ContentAssetType.Document;
+    public AssetStorageProvider StorageProvider { get; set; } = AssetStorageProvider.ExternalUrl;
+    public string? Bucket { get; set; }
+    public string? ObjectKey { get; set; }
+    public string? MimeType { get; set; }
+    public long? FileSizeBytes { get; set; }
+    public string? ChecksumSha256 { get; set; }
+    public ContentVisibility Visibility { get; set; } = ContentVisibility.Members;
+    public string? PreviewUrl { get; set; }
+    public ContentStatus Status { get; set; } = ContentStatus.Active;
+    public int SortOrder { get; set; }
+    public JsonElement AccessRules { get; set; } = JsonDefaults.Object();
+    public string Source { get; set; } = "manual";
+    public int DownloadCount { get; set; }
+    public AssetUploadStatus UploadStatus { get; set; } = AssetUploadStatus.NotRequired;
+    public DateTimeOffset? VerifiedAt { get; set; }
+    public long? VerifiedSizeBytes { get; set; }
+    public string? VerifiedChecksumSha256 { get; set; }
+    public JsonElement VerificationDetails { get; set; } = JsonDefaults.Object();
+    public string? PreviewObjectKey { get; set; }
+    public AssetPreviewStatus PreviewStatus { get; set; } = AssetPreviewStatus.None;
+    public JsonElement SecurityFlags { get; set; } = JsonDefaults.Object();
+    public JsonElement Metadata { get; set; } = JsonDefaults.Object();
+}
+
+public sealed class ContentImportJob : AuditableTenantEntity
+{
+    public Guid? CreatedBy { get; set; }
+    public Guid? TargetRegionId { get; set; }
+    public Guid? TargetSubjectId { get; set; }
+    public Guid? TargetCategoryId { get; set; }
+    public Guid? TargetContentNodeId { get; set; }
+    public Guid? TargetQuestionBankId { get; set; }
+    public ContentImportType ImportType { get; set; } = ContentImportType.Questions;
+    public ImportSourceFormat SourceFormat { get; set; } = ImportSourceFormat.Json;
+    public ContentImportStatus Status { get; set; } = ContentImportStatus.Preview;
+    public string? SourceName { get; set; }
+    public string? SourceHash { get; set; }
+    public bool DryRun { get; set; } = true;
+    public int TotalCount { get; set; }
+    public int ValidCount { get; set; }
+    public int ErrorCount { get; set; }
+    public int WarningCount { get; set; }
+    public int InsertedCount { get; set; }
+    public int UpdatedCount { get; set; }
+    public int SkippedCount { get; set; }
+    public JsonElement Summary { get; set; } = JsonDefaults.Object();
+    public JsonElement RawPayload { get; set; } = JsonDefaults.Array();
+    public JsonElement NormalizedPayload { get; set; } = JsonDefaults.Array();
+    public string? ErrorMessage { get; set; }
+    public DateTimeOffset? StartedAt { get; set; }
+    public DateTimeOffset? FinishedAt { get; set; }
+}
+
+public sealed class ContentImportItem : AuditableTenantEntity
+{
+    public Guid JobId { get; set; }
+    public int RowNo { get; set; }
+    public string? ExternalId { get; set; }
+    public ContentImportItemStatus Status { get; set; } = ContentImportItemStatus.Valid;
+    public string? TargetType { get; set; }
+    public Guid? TargetId { get; set; }
+    public JsonElement SourcePayload { get; set; } = JsonDefaults.Object();
+    public JsonElement NormalizedPayload { get; set; } = JsonDefaults.Object();
+    public string? ContentHash { get; set; }
+    public int IssuesCount { get; set; }
+}
+
+public sealed class ContentImportIssue : AuditableTenantEntity
+{
+    public Guid JobId { get; set; }
+    public Guid? ItemId { get; set; }
+    public int? RowNo { get; set; }
+    public ImportIssueSeverity Severity { get; set; } = ImportIssueSeverity.Error;
+    public string Code { get; set; } = string.Empty;
+    public string? FieldPath { get; set; }
+    public string Message { get; set; } = string.Empty;
+    public JsonElement Details { get; set; } = JsonDefaults.Object();
+}
+
+public sealed class ImageAsset : AuditableTenantEntity
+{
+    public string? LegacyId { get; set; }
+    public string? Title { get; set; }
+    public string? Category { get; set; }
+    public string? FileName { get; set; }
+    public bool IsPublic { get; set; }
+    public string? CdnUrl { get; set; }
+    public JsonElement Metadata { get; set; } = JsonDefaults.Object();
+}
+
+public sealed class AppAsset : AuditableTenantEntity
+{
+    public string? LegacyId { get; set; }
+    public string AssetKey { get; set; } = string.Empty;
+    public string? FileName { get; set; }
+    public string? Description { get; set; }
+    public JsonElement Metadata { get; set; } = JsonDefaults.Object();
+}
+
+public sealed class VideoExplanation : AuditableTenantEntity
+{
+    public Guid? SubjectId { get; set; }
+    public string? LegacyId { get; set; }
+    public string? LegacySubjectId { get; set; }
+    public string Title { get; set; } = string.Empty;
+    public string? Description { get; set; }
+    public string? VideoUrl { get; set; }
+    public string? ThumbnailUrl { get; set; }
+    public int? DurationSeconds { get; set; }
+    public JsonElement KnowledgeTags { get; set; } = JsonDefaults.Array();
+    public bool IsGeneral { get; set; }
+    public int? Difficulty { get; set; }
+    public int SortOrder { get; set; }
+    public bool IsActive { get; set; } = true;
+    public string? SourceHash { get; set; }
+    public JsonElement Metadata { get; set; } = JsonDefaults.Object();
+}
+
+public sealed class QuestionVideo : AuditableTenantEntity
+{
+    public Guid? QuestionId { get; set; }
+    public Guid? VideoId { get; set; }
+    public string? LegacyId { get; set; }
+    public string? LegacyQuestionId { get; set; }
+    public string? LegacyVideoId { get; set; }
+    public QuestionVideoType VideoType { get; set; } = QuestionVideoType.Specific;
+    public int SortOrder { get; set; }
+    public JsonElement Metadata { get; set; } = JsonDefaults.Object();
+}
+
+public enum ContentAssetType
+{
+    Pdf,
+    Video,
+    Image,
+    Audio,
+    Document,
+    Package,
+    Link,
+    Other
+}
+
+public enum AssetStorageProvider
+{
+    ExternalUrl,
+    SupabaseStorage,
+    AliyunOss,
+    TencentCos,
+    QiniuKodo,
+    LocalDev
+}
+
+public enum AssetUploadStatus
+{
+    NotRequired,
+    Pending,
+    Verified,
+    Failed
+}
+
+public enum AssetPreviewStatus
+{
+    None,
+    Pending,
+    Ready,
+    Failed
+}
+
+public enum ContentImportType
+{
+    Questions,
+    Vocabulary,
+    Handbook,
+    Scoreline,
+    Assets,
+    Videos
+}
+
+public enum ImportSourceFormat
+{
+    Json,
+    Excel,
+    Csv,
+    Pocketbase,
+    Api
+}
+
+public enum ContentImportStatus
+{
+    Preview,
+    Pending,
+    Importing,
+    Completed,
+    CompletedWithErrors,
+    Failed,
+    Rejected
+}
+
+public enum ContentImportItemStatus
+{
+    Valid,
+    Invalid,
+    Inserted,
+    Updated,
+    Skipped,
+    Failed
+}
+
+public enum ImportIssueSeverity
+{
+    Error,
+    Warning
+}
+
+public enum QuestionVideoType
+{
+    Specific,
+    General,
+    Related
+}

Tiku.Domain/Content/StudyContentEntities.cs

@@ -130,8 +130,8 @@ public sealed class QuestionTypeGroup : AuditableTenantEntity
 
 public sealed class SubjectShare : AuditableTenantEntity
 {
-    public Guid? SourceSubjectId { get; set; }
+    public Guid SourceSubjectId { get; set; }
-    public Guid? TargetSubjectId { get; set; }
+    public Guid TargetSubjectId { get; set; }
     public string? LegacyId { get; set; }
     public string? LegacySourceSubjectId { get; set; }
     public string? LegacyTargetSubjectId { get; set; }

Tiku.Infrastructure/Persistence/Configurations/AssetConfigurations.cs

@@ -0,0 +1,299 @@
+using Microsoft.EntityFrameworkCore;
+using Microsoft.EntityFrameworkCore.Metadata.Builders;
+using Tiku.Domain.Catalog;
+using Tiku.Domain.Content;
+using Tiku.Domain.Identity;
+using Tiku.Domain.QuestionBanks;
+
+namespace Tiku.Infrastructure.Persistence.Configurations;
+
+internal sealed class ContentAssetConfiguration : IEntityTypeConfiguration<ContentAsset>
+{
+    public void Configure(EntityTypeBuilder<ContentAsset> builder)
+    {
+        builder.ConfigureTenantEntity("content_assets");
+        builder.ConfigureTimestamps();
+        builder.Property(entity => entity.LegacyId).HasMaxLength(64);
+        builder.Property(entity => entity.AssetKey).HasMaxLength(200);
+        builder.Property(entity => entity.Title).HasMaxLength(300);
+        builder.Property(entity => entity.Category).HasMaxLength(100);
+        builder.Property(entity => entity.FileName).HasMaxLength(500);
+        builder.Property(entity => entity.CdnUrl).HasMaxLength(2048);
+        builder.Property(entity => entity.AssetType).HasSnakeCaseEnum();
+        builder.Property(entity => entity.StorageProvider).HasSnakeCaseEnum();
+        builder.Property(entity => entity.Bucket).HasMaxLength(200);
+        builder.Property(entity => entity.ObjectKey).HasMaxLength(1000);
+        builder.Property(entity => entity.MimeType).HasMaxLength(200);
+        builder.Property(entity => entity.ChecksumSha256).HasMaxLength(64);
+        builder.Property(entity => entity.Visibility).HasSnakeCaseEnum();
+        builder.Property(entity => entity.PreviewUrl).HasMaxLength(2048);
+        builder.Property(entity => entity.Status).HasSnakeCaseEnum();
+        builder.Property(entity => entity.AccessRules).IsJson("{}");
+        builder.Property(entity => entity.Source).HasMaxLength(50);
+        builder.Property(entity => entity.UploadStatus).HasSnakeCaseEnum();
+        builder.Property(entity => entity.VerifiedChecksumSha256).HasMaxLength(64);
+        builder.Property(entity => entity.VerificationDetails).IsJson("{}");
+        builder.Property(entity => entity.PreviewObjectKey).HasMaxLength(1000);
+        builder.Property(entity => entity.PreviewStatus).HasSnakeCaseEnum();
+        builder.Property(entity => entity.SecurityFlags).IsJson("{}");
+        builder.Property(entity => entity.Metadata).IsJson("{}");
+        builder.HasIndex(entity => new { entity.TenantId, entity.LegacyId }).IsUnique();
+        builder.HasIndex(entity => new
+        {
+            entity.TenantId,
+            entity.Status,
+            entity.Visibility,
+            entity.AssetType,
+            entity.RegionId,
+            entity.SubjectId,
+            entity.CategoryId,
+            entity.SortOrder
+        });
+        builder.HasIndex(entity => new
+        {
+            entity.TenantId,
+            entity.StorageProvider,
+            entity.Bucket,
+            entity.ObjectKey
+        });
+        builder.HasIndex(entity => new { entity.TenantId, entity.ChecksumSha256 })
+            .HasFilter("checksum_sha256 is not null");
+        builder.HasIndex(entity => new
+        {
+            entity.TenantId,
+            entity.UploadStatus,
+            entity.Status,
+            entity.UpdatedAt
+        });
+        builder.HasIndex(entity => new { entity.TenantId, entity.PreviewStatus })
+            .HasFilter("preview_status <> 'none'");
+        builder.ToTable(table =>
+        {
+            table.HasCheckConstraint("ck_content_assets_file_size", "file_size_bytes is null or file_size_bytes >= 0");
+            table.HasCheckConstraint("ck_content_assets_download_count", "download_count >= 0");
+            table.HasCheckConstraint("ck_content_assets_verified_size", "verified_size_bytes is null or verified_size_bytes >= 0");
+            table.HasCheckConstraint(
+                "ck_content_assets_verified_checksum",
+                "verified_checksum_sha256 is null or verified_checksum_sha256 ~ '^[a-f0-9]{64}$'");
+        });
+
+        builder.HasOne<Region>().WithMany()
+            .HasForeignKey(entity => new { entity.TenantId, entity.RegionId })
+            .HasPrincipalKey(entity => new { entity.TenantId, entity.Id })
+            .OnDelete(DeleteBehavior.Restrict);
+        builder.HasOne<Subject>().WithMany()
+            .HasForeignKey(entity => new { entity.TenantId, entity.SubjectId })
+            .HasPrincipalKey(entity => new { entity.TenantId, entity.Id })
+            .OnDelete(DeleteBehavior.Restrict);
+        builder.HasOne<Category>().WithMany()
+            .HasForeignKey(entity => new { entity.TenantId, entity.CategoryId })
+            .HasPrincipalKey(entity => new { entity.TenantId, entity.Id })
+            .OnDelete(DeleteBehavior.Restrict);
+        builder.HasOne<ContentNode>().WithMany()
+            .HasForeignKey(entity => new { entity.TenantId, entity.ContentNodeId })
+            .HasPrincipalKey(entity => new { entity.TenantId, entity.Id })
+            .OnDelete(DeleteBehavior.Restrict);
+        builder.HasOne<User>().WithMany()
+            .HasForeignKey(entity => entity.CreatedBy)
+            .OnDelete(DeleteBehavior.SetNull);
+        builder.HasOne<User>().WithMany()
+            .HasForeignKey(entity => entity.UpdatedBy)
+            .OnDelete(DeleteBehavior.SetNull);
+        builder.HasOne<User>().WithMany()
+            .HasForeignKey(entity => entity.VerifiedBy)
+            .OnDelete(DeleteBehavior.SetNull);
+    }
+}
+
+internal sealed class ContentImportJobConfiguration : IEntityTypeConfiguration<ContentImportJob>
+{
+    public void Configure(EntityTypeBuilder<ContentImportJob> builder)
+    {
+        builder.ConfigureTenantEntity("content_import_jobs");
+        builder.ConfigureTimestamps();
+        builder.Property(entity => entity.ImportType).HasSnakeCaseEnum();
+        builder.Property(entity => entity.SourceFormat).HasSnakeCaseEnum();
+        builder.Property(entity => entity.Status).HasSnakeCaseEnum();
+        builder.Property(entity => entity.SourceName).HasMaxLength(500);
+        builder.Property(entity => entity.SourceHash).HasMaxLength(128);
+        builder.Property(entity => entity.Summary).IsJson("{}");
+        builder.Property(entity => entity.RawPayload).IsJson("[]");
+        builder.Property(entity => entity.NormalizedPayload).IsJson("[]");
+        builder.HasIndex(entity => new
+        {
+            entity.TenantId,
+            entity.ImportType,
+            entity.Status,
+            entity.CreatedAt
+        });
+        builder.ToTable(table =>
+        {
+            table.HasCheckConstraint("ck_content_import_jobs_counts", "total_count >= 0 and valid_count >= 0 and error_count >= 0 and warning_count >= 0 and inserted_count >= 0 and updated_count >= 0 and skipped_count >= 0");
+        });
+
+        builder.HasOne<User>().WithMany()
+            .HasForeignKey(entity => entity.CreatedBy)
+            .OnDelete(DeleteBehavior.SetNull);
+        builder.HasOne<Region>().WithMany()
+            .HasForeignKey(entity => new { entity.TenantId, entity.TargetRegionId })
+            .HasPrincipalKey(entity => new { entity.TenantId, entity.Id })
+            .OnDelete(DeleteBehavior.Restrict);
+        builder.HasOne<Subject>().WithMany()
+            .HasForeignKey(entity => new { entity.TenantId, entity.TargetSubjectId })
+            .HasPrincipalKey(entity => new { entity.TenantId, entity.Id })
+            .OnDelete(DeleteBehavior.Restrict);
+        builder.HasOne<Category>().WithMany()
+            .HasForeignKey(entity => new { entity.TenantId, entity.TargetCategoryId })
+            .HasPrincipalKey(entity => new { entity.TenantId, entity.Id })
+            .OnDelete(DeleteBehavior.Restrict);
+        builder.HasOne<ContentNode>().WithMany()
+            .HasForeignKey(entity => new { entity.TenantId, entity.TargetContentNodeId })
+            .HasPrincipalKey(entity => new { entity.TenantId, entity.Id })
+            .OnDelete(DeleteBehavior.Restrict);
+        builder.HasOne<QuestionBank>().WithMany()
+            .HasForeignKey(entity => new { entity.TenantId, entity.TargetQuestionBankId })
+            .HasPrincipalKey(entity => new { entity.TenantId, entity.Id })
+            .OnDelete(DeleteBehavior.Restrict);
+    }
+}
+
+internal sealed class ContentImportItemConfiguration : IEntityTypeConfiguration<ContentImportItem>
+{
+    public void Configure(EntityTypeBuilder<ContentImportItem> builder)
+    {
+        builder.ConfigureTenantEntity("content_import_items");
+        builder.ConfigureTimestamps();
+        builder.Property(entity => entity.ExternalId).HasMaxLength(200);
+        builder.Property(entity => entity.Status).HasSnakeCaseEnum();
+        builder.Property(entity => entity.TargetType).HasMaxLength(100);
+        builder.Property(entity => entity.SourcePayload).IsJson("{}");
+        builder.Property(entity => entity.NormalizedPayload).IsJson("{}");
+        builder.Property(entity => entity.ContentHash).HasMaxLength(128);
+        builder.HasIndex(entity => new { entity.JobId, entity.RowNo }).IsUnique();
+        builder.HasIndex(entity => new { entity.TenantId, entity.JobId, entity.Status, entity.RowNo });
+        builder.ToTable(table =>
+        {
+            table.HasCheckConstraint("ck_content_import_items_row_no", "row_no >= 0");
+            table.HasCheckConstraint("ck_content_import_items_issues_count", "issues_count >= 0");
+        });
+
+        builder.HasOne<ContentImportJob>().WithMany()
+            .HasForeignKey(entity => new { entity.TenantId, entity.JobId })
+            .HasPrincipalKey(entity => new { entity.TenantId, entity.Id })
+            .OnDelete(DeleteBehavior.Cascade);
+    }
+}
+
+internal sealed class ContentImportIssueConfiguration : IEntityTypeConfiguration<ContentImportIssue>
+{
+    public void Configure(EntityTypeBuilder<ContentImportIssue> builder)
+    {
+        builder.ConfigureTenantEntity("content_import_issues");
+        builder.ConfigureTimestamps();
+        builder.Property(entity => entity.Severity).HasSnakeCaseEnum();
+        builder.Property(entity => entity.Code).HasMaxLength(100);
+        builder.Property(entity => entity.FieldPath).HasMaxLength(500);
+        builder.Property(entity => entity.Message).HasMaxLength(2000);
+        builder.Property(entity => entity.Details).IsJson("{}");
+        builder.HasIndex(entity => new { entity.TenantId, entity.JobId, entity.Severity, entity.RowNo });
+
+        builder.HasOne<ContentImportJob>().WithMany()
+            .HasForeignKey(entity => new { entity.TenantId, entity.JobId })
+            .HasPrincipalKey(entity => new { entity.TenantId, entity.Id })
+            .OnDelete(DeleteBehavior.Cascade);
+        builder.HasOne<ContentImportItem>().WithMany()
+            .HasForeignKey(entity => new { entity.TenantId, entity.ItemId })
+            .HasPrincipalKey(entity => new { entity.TenantId, entity.Id })
+            .OnDelete(DeleteBehavior.Cascade);
+    }
+}
+
+internal sealed class ImageAssetConfiguration : IEntityTypeConfiguration<ImageAsset>
+{
+    public void Configure(EntityTypeBuilder<ImageAsset> builder)
+    {
+        builder.ConfigureTenantEntity("images");
+        builder.ConfigureTimestamps();
+        builder.Property(entity => entity.LegacyId).HasMaxLength(64);
+        builder.Property(entity => entity.Title).HasMaxLength(300);
+        builder.Property(entity => entity.Category).HasMaxLength(100);
+        builder.Property(entity => entity.FileName).HasMaxLength(500);
+        builder.Property(entity => entity.CdnUrl).HasMaxLength(2048);
+        builder.Property(entity => entity.Metadata).IsJson("{}");
+        builder.HasIndex(entity => new { entity.TenantId, entity.LegacyId }).IsUnique();
+        builder.HasIndex(entity => new { entity.TenantId, entity.Category, entity.IsPublic });
+    }
+}
+
+internal sealed class AppAssetConfiguration : IEntityTypeConfiguration<AppAsset>
+{
+    public void Configure(EntityTypeBuilder<AppAsset> builder)
+    {
+        builder.ConfigureTenantEntity("app_assets");
+        builder.ConfigureTimestamps();
+        builder.Property(entity => entity.LegacyId).HasMaxLength(64);
+        builder.Property(entity => entity.AssetKey).HasMaxLength(200);
+        builder.Property(entity => entity.FileName).HasMaxLength(500);
+        builder.Property(entity => entity.Description).HasMaxLength(1000);
+        builder.Property(entity => entity.Metadata).IsJson("{}");
+        builder.HasIndex(entity => new { entity.TenantId, entity.LegacyId }).IsUnique();
+        builder.HasIndex(entity => new { entity.TenantId, entity.AssetKey }).IsUnique();
+    }
+}
+
+internal sealed class VideoExplanationConfiguration : IEntityTypeConfiguration<VideoExplanation>
+{
+    public void Configure(EntityTypeBuilder<VideoExplanation> builder)
+    {
+        builder.ConfigureTenantEntity("video_explanations");
+        builder.ConfigureTimestamps();
+        builder.Property(entity => entity.LegacyId).HasMaxLength(64);
+        builder.Property(entity => entity.LegacySubjectId).HasMaxLength(64);
+        builder.Property(entity => entity.Title).HasMaxLength(300);
+        builder.Property(entity => entity.VideoUrl).HasMaxLength(2048);
+        builder.Property(entity => entity.ThumbnailUrl).HasMaxLength(2048);
+        builder.Property(entity => entity.KnowledgeTags).IsJson("[]");
+        builder.Property(entity => entity.SourceHash).HasMaxLength(128);
+        builder.Property(entity => entity.Metadata).IsJson("{}");
+        builder.HasIndex(entity => new { entity.TenantId, entity.LegacyId }).IsUnique();
+        builder.HasIndex(entity => new { entity.TenantId, entity.SourceHash })
+            .HasFilter("source_hash is not null");
+        builder.HasIndex(entity => new { entity.TenantId, entity.SubjectId, entity.IsActive, entity.SortOrder });
+
+        builder.HasOne<Subject>().WithMany()
+            .HasForeignKey(entity => new { entity.TenantId, entity.SubjectId })
+            .HasPrincipalKey(entity => new { entity.TenantId, entity.Id })
+            .OnDelete(DeleteBehavior.Restrict);
+    }
+}
+
+internal sealed class QuestionVideoConfiguration : IEntityTypeConfiguration<QuestionVideo>
+{
+    public void Configure(EntityTypeBuilder<QuestionVideo> builder)
+    {
+        builder.ConfigureTenantEntity("question_videos");
+        builder.ConfigureTimestamps();
+        builder.Property(entity => entity.LegacyId).HasMaxLength(64);
+        builder.Property(entity => entity.LegacyQuestionId).HasMaxLength(64);
+        builder.Property(entity => entity.LegacyVideoId).HasMaxLength(64);
+        builder.Property(entity => entity.VideoType).HasSnakeCaseEnum();
+        builder.Property(entity => entity.Metadata).IsJson("{}");
+        builder.HasIndex(entity => new { entity.TenantId, entity.LegacyId }).IsUnique();
+        builder.HasIndex(entity => new
+        {
+            entity.TenantId,
+            entity.QuestionId,
+            entity.VideoId,
+            entity.VideoType
+        }).IsUnique();
+
+        builder.HasOne<Question>().WithMany()
+            .HasForeignKey(entity => new { entity.TenantId, entity.QuestionId })
+            .HasPrincipalKey(entity => new { entity.TenantId, entity.Id })
+            .OnDelete(DeleteBehavior.Cascade);
+        builder.HasOne<VideoExplanation>().WithMany()
+            .HasForeignKey(entity => new { entity.TenantId, entity.VideoId })
+            .HasPrincipalKey(entity => new { entity.TenantId, entity.Id })
+            .OnDelete(DeleteBehavior.Cascade);
+    }
+}

Tiku.Infrastructure/Persistence/Configurations/StudyContentConfigurations.cs

@@ -3,6 +3,7 @@ using Microsoft.EntityFrameworkCore.Metadata.Builders;
 using Tiku.Domain.Catalog;
 using Tiku.Domain.Content;
 using Tiku.Domain.Identity;
+using Tiku.Domain.Tenancy;
 
 namespace Tiku.Infrastructure.Persistence.Configurations;
 
@@ -14,7 +15,6 @@ internal sealed class VocabularyUnitConfiguration : IEntityTypeConfiguration<Voc
         builder.ConfigureTimestamps();
         builder.Property(entity => entity.LegacyId).HasMaxLength(64);
         builder.Property(entity => entity.Name).HasMaxLength(300);
-        builder.Property(entity => entity.Description).HasMaxLength(2000);
         builder.Property(entity => entity.SourceHash).HasMaxLength(128);
         builder.Property(entity => entity.Metadata).IsJson("{}");
         builder.HasIndex(entity => new { entity.TenantId, entity.LegacyId }).IsUnique();
@@ -51,10 +51,7 @@ internal sealed class VocabularyWordConfiguration : IEntityTypeConfiguration<Voc
         builder.ConfigureTimestamps();
         builder.Property(entity => entity.LegacyId).HasMaxLength(64);
         builder.Property(entity => entity.Word).HasMaxLength(300);
-        builder.Property(entity => entity.Phonetic).HasMaxLength(200);
+        builder.Property(entity => entity.Phonetic).HasMaxLength(300);
-        builder.Property(entity => entity.Meaning).HasMaxLength(2000);
-        builder.Property(entity => entity.Example).HasMaxLength(4000);
-        builder.Property(entity => entity.ExampleTranslation).HasMaxLength(4000);
         builder.Property(entity => entity.SourceHash).HasMaxLength(128);
         builder.Property(entity => entity.Tags).IsJson("[]");
         builder.Property(entity => entity.Metadata).IsJson("{}");
@@ -98,17 +95,12 @@ internal sealed class UserWordProgressConfiguration : IEntityTypeConfiguration<U
     {
         builder.ConfigureTenantEntity("user_word_progress");
         builder.ConfigureTimestamps();
-        builder.Property(entity => entity.LegacyId).HasMaxLength(64);
-        builder.Property(entity => entity.LegacyUserId).HasMaxLength(64);
-        builder.Property(entity => entity.LegacyWordId).HasMaxLength(64);
         builder.Property(entity => entity.Status).HasSnakeCaseEnum();
         builder.Property(entity => entity.EaseFactor).HasPrecision(4, 2).HasDefaultValue(2.50m);
         builder.Property(entity => entity.LastResult).HasNullableSnakeCaseEnum();
         builder.Property(entity => entity.DueLevel).HasSnakeCaseEnum();
         builder.Property(entity => entity.Metadata).IsJson("{}");
-        builder.HasIndex(entity => new { entity.TenantId, entity.LegacyId }).IsUnique();
         builder.HasIndex(entity => new { entity.TenantId, entity.UserId, entity.WordId }).IsUnique();
-        builder.HasIndex(entity => new { entity.TenantId, entity.UserId, entity.Status });
         builder.HasIndex(entity => new
         {
             entity.TenantId,
@@ -141,11 +133,7 @@ internal sealed class UserWordFavoriteConfiguration : IEntityTypeConfiguration<U
     {
         builder.ConfigureTenantEntity("user_word_favorites");
         builder.ConfigureTimestamps();
-        builder.Property(entity => entity.LegacyId).HasMaxLength(64);
+        builder.Property(entity => entity.Note).HasMaxLength(1000);
-        builder.Property(entity => entity.LegacyUserId).HasMaxLength(64);
-        builder.Property(entity => entity.LegacyWordId).HasMaxLength(64);
-        builder.Property(entity => entity.Note).HasMaxLength(2000);
-        builder.HasIndex(entity => new { entity.TenantId, entity.LegacyId }).IsUnique();
         builder.HasIndex(entity => new { entity.TenantId, entity.UserId, entity.WordId }).IsUnique();
 
         builder.HasOne<User>().WithMany()
@@ -169,7 +157,6 @@ internal sealed class HandbookSubjectConfiguration : IEntityTypeConfiguration<Ha
         builder.Property(entity => entity.Type).HasNullableSnakeCaseEnum();
         builder.Property(entity => entity.Icon).HasMaxLength(2048);
         builder.Property(entity => entity.Color).HasMaxLength(50);
-        builder.Property(entity => entity.Description).HasMaxLength(2000);
         builder.Property(entity => entity.MajorLegacyIds).IsJson("[]");
         builder.Property(entity => entity.SourceHash).HasMaxLength(128);
         builder.Property(entity => entity.Metadata).IsJson("{}");
@@ -215,7 +202,6 @@ internal sealed class HandbookChapterConfiguration : IEntityTypeConfiguration<Ha
         builder.ConfigureTimestamps();
         builder.Property(entity => entity.LegacyId).HasMaxLength(64);
         builder.Property(entity => entity.Name).HasMaxLength(300);
-        builder.Property(entity => entity.Description).HasMaxLength(2000);
         builder.Property(entity => entity.SourceHash).HasMaxLength(128);
         builder.Property(entity => entity.Metadata).IsJson("{}");
         builder.HasIndex(entity => new { entity.TenantId, entity.LegacyId }).IsUnique();
@@ -251,8 +237,7 @@ internal sealed class HandbookEntryConfiguration : IEntityTypeConfiguration<Hand
         builder.ConfigureTenantEntity("handbook_entries");
         builder.ConfigureTimestamps();
         builder.Property(entity => entity.LegacyId).HasMaxLength(64);
-        builder.Property(entity => entity.Title).HasMaxLength(300);
+        builder.Property(entity => entity.Title).HasMaxLength(500);
-        builder.Property(entity => entity.Summary).HasMaxLength(2000);
         builder.Property(entity => entity.Tags).IsJson("[]");
         builder.Property(entity => entity.SourceHash).HasMaxLength(128);
         builder.Property(entity => entity.Metadata).IsJson("{}");
@@ -289,7 +274,7 @@ internal sealed class QuestionTypeGroupConfiguration : IEntityTypeConfiguration<
         builder.ConfigureTenantEntity("question_type_groups");
         builder.ConfigureTimestamps();
         builder.Property(entity => entity.LegacyId).HasMaxLength(64);
-        builder.Property(entity => entity.DisplayName).HasMaxLength(300);
+        builder.Property(entity => entity.DisplayName).HasMaxLength(200);
         builder.Property(entity => entity.Types).IsJson("[]");
         builder.HasIndex(entity => new { entity.TenantId, entity.LegacyId }).IsUnique();
         builder.HasIndex(entity => new
@@ -311,18 +296,19 @@ internal sealed class SubjectShareConfiguration : IEntityTypeConfiguration<Subje
 {
     public void Configure(EntityTypeBuilder<SubjectShare> builder)
     {
-        builder.ConfigureTenantEntity("subject_shares");
+        builder.ToTable("subject_shares");
-        builder.ConfigureTimestamps();
+        builder.HasKey(entity => new
-        builder.Property(entity => entity.LegacyId).HasMaxLength(64);
-        builder.Property(entity => entity.LegacySourceSubjectId).HasMaxLength(64);
-        builder.Property(entity => entity.LegacyTargetSubjectId).HasMaxLength(64);
-        builder.HasIndex(entity => new { entity.TenantId, entity.LegacyId }).IsUnique();
-        builder.HasIndex(entity => new
         {
             entity.TenantId,
             entity.SourceSubjectId,
             entity.TargetSubjectId
-        }).IsUnique();
+        });
+        builder.Property(entity => entity.CreatedAt).HasDefaultValueSql("now()");
+        builder.HasIndex(entity => new { entity.TenantId, entity.TargetSubjectId });
+
+        builder.HasOne<Tenant>().WithMany()
+            .HasForeignKey(entity => entity.TenantId)
+            .OnDelete(DeleteBehavior.Cascade);
 
         builder.HasOne<Subject>().WithMany()
             .HasForeignKey(entity => new { entity.TenantId, entity.SourceSubjectId })

Tiku.Infrastructure/Persistence/Migrations/20260725211732_AddContentAssetsAndImportPersistence.cs

@@ -0,0 +1,630 @@
+using System;
+using System.Text.Json;
+using Microsoft.EntityFrameworkCore.Migrations;
+
+#nullable disable
+
+namespace Tiku.Infrastructure.Persistence.Migrations
+{
+    /// <inheritdoc />
+    public partial class AddContentAssetsAndImportPersistence : Migration
+    {
+        /// <inheritdoc />
+        protected override void Up(MigrationBuilder migrationBuilder)
+        {
+            migrationBuilder.CreateTable(
+                name: "app_assets",
+                columns: table => new
+                {
+                    id = table.Column<Guid>(type: "uuid", nullable: false, defaultValueSql: "gen_random_uuid()"),
+                    legacy_id = table.Column<string>(type: "character varying(64)", maxLength: 64, nullable: true),
+                    asset_key = table.Column<string>(type: "character varying(200)", maxLength: 200, nullable: false),
+                    file_name = table.Column<string>(type: "character varying(500)", maxLength: 500, nullable: true),
+                    description = table.Column<string>(type: "character varying(1000)", maxLength: 1000, nullable: true),
+                    metadata = table.Column<JsonElement>(type: "jsonb", nullable: false, defaultValueSql: "'{}'::jsonb"),
+                    tenant_id = table.Column<Guid>(type: "uuid", nullable: false),
+                    created_at = table.Column<DateTimeOffset>(type: "timestamp with time zone", nullable: false, defaultValueSql: "now()"),
+                    updated_at = table.Column<DateTimeOffset>(type: "timestamp with time zone", nullable: false, defaultValueSql: "now()")
+                },
+                constraints: table =>
+                {
+                    table.PrimaryKey("pk_app_assets", x => x.id);
+                    table.UniqueConstraint("ak_app_assets_tenant_id_id", x => new { x.tenant_id, x.id });
+                    table.ForeignKey(
+                        name: "fk_app_assets_tenants_tenant_id",
+                        column: x => x.tenant_id,
+                        principalTable: "tenants",
+                        principalColumn: "id",
+                        onDelete: ReferentialAction.Cascade);
+                });
+
+            migrationBuilder.CreateTable(
+                name: "content_assets",
+                columns: table => new
+                {
+                    id = table.Column<Guid>(type: "uuid", nullable: false, defaultValueSql: "gen_random_uuid()"),
+                    region_id = table.Column<Guid>(type: "uuid", nullable: true),
+                    subject_id = table.Column<Guid>(type: "uuid", nullable: true),
+                    category_id = table.Column<Guid>(type: "uuid", nullable: true),
+                    content_node_id = table.Column<Guid>(type: "uuid", nullable: true),
+                    created_by = table.Column<Guid>(type: "uuid", nullable: true),
+                    updated_by = table.Column<Guid>(type: "uuid", nullable: true),
+                    verified_by = table.Column<Guid>(type: "uuid", nullable: true),
+                    legacy_id = table.Column<string>(type: "character varying(64)", maxLength: 64, nullable: true),
+                    asset_key = table.Column<string>(type: "character varying(200)", maxLength: 200, nullable: true),
+                    title = table.Column<string>(type: "character varying(300)", maxLength: 300, nullable: true),
+                    category = table.Column<string>(type: "character varying(100)", maxLength: 100, nullable: true),
+                    description = table.Column<string>(type: "text", nullable: true),
+                    file_name = table.Column<string>(type: "character varying(500)", maxLength: 500, nullable: true),
+                    cdn_url = table.Column<string>(type: "character varying(2048)", maxLength: 2048, nullable: true),
+                    is_public = table.Column<bool>(type: "boolean", nullable: false),
+                    asset_type = table.Column<string>(type: "character varying(32)", maxLength: 32, nullable: false),
+                    storage_provider = table.Column<string>(type: "character varying(32)", maxLength: 32, nullable: false),
+                    bucket = table.Column<string>(type: "character varying(200)", maxLength: 200, nullable: true),
+                    object_key = table.Column<string>(type: "character varying(1000)", maxLength: 1000, nullable: true),
+                    mime_type = table.Column<string>(type: "character varying(200)", maxLength: 200, nullable: true),
+                    file_size_bytes = table.Column<long>(type: "bigint", nullable: true),
+                    checksum_sha256 = table.Column<string>(type: "character varying(64)", maxLength: 64, nullable: true),
+                    visibility = table.Column<string>(type: "character varying(32)", maxLength: 32, nullable: false),
+                    preview_url = table.Column<string>(type: "character varying(2048)", maxLength: 2048, nullable: true),
+                    status = table.Column<string>(type: "character varying(32)", maxLength: 32, nullable: false),
+                    sort_order = table.Column<int>(type: "integer", nullable: false),
+                    access_rules = table.Column<JsonElement>(type: "jsonb", nullable: false, defaultValueSql: "'{}'::jsonb"),
+                    source = table.Column<string>(type: "character varying(50)", maxLength: 50, nullable: false),
+                    download_count = table.Column<int>(type: "integer", nullable: false),
+                    upload_status = table.Column<string>(type: "character varying(32)", maxLength: 32, nullable: false),
+                    verified_at = table.Column<DateTimeOffset>(type: "timestamp with time zone", nullable: true),
+                    verified_size_bytes = table.Column<long>(type: "bigint", nullable: true),
+                    verified_checksum_sha256 = table.Column<string>(type: "character varying(64)", maxLength: 64, nullable: true),
+                    verification_details = table.Column<JsonElement>(type: "jsonb", nullable: false, defaultValueSql: "'{}'::jsonb"),
+                    preview_object_key = table.Column<string>(type: "character varying(1000)", maxLength: 1000, nullable: true),
+                    preview_status = table.Column<string>(type: "character varying(32)", maxLength: 32, nullable: false),
+                    security_flags = table.Column<JsonElement>(type: "jsonb", nullable: false, defaultValueSql: "'{}'::jsonb"),
+                    metadata = table.Column<JsonElement>(type: "jsonb", nullable: false, defaultValueSql: "'{}'::jsonb"),
+                    tenant_id = table.Column<Guid>(type: "uuid", nullable: false),
+                    created_at = table.Column<DateTimeOffset>(type: "timestamp with time zone", nullable: false, defaultValueSql: "now()"),
+                    updated_at = table.Column<DateTimeOffset>(type: "timestamp with time zone", nullable: false, defaultValueSql: "now()")
+                },
+                constraints: table =>
+                {
+                    table.PrimaryKey("pk_content_assets", x => x.id);
+                    table.UniqueConstraint("ak_content_assets_tenant_id_id", x => new { x.tenant_id, x.id });
+                    table.CheckConstraint("ck_content_assets_download_count", "download_count >= 0");
+                    table.CheckConstraint("ck_content_assets_file_size", "file_size_bytes is null or file_size_bytes >= 0");
+                    table.CheckConstraint("ck_content_assets_verified_checksum", "verified_checksum_sha256 is null or verified_checksum_sha256 ~ '^[a-f0-9]{64}$'");
+                    table.CheckConstraint("ck_content_assets_verified_size", "verified_size_bytes is null or verified_size_bytes >= 0");
+                    table.ForeignKey(
+                        name: "fk_content_assets_categories_tenant_id_category_id",
+                        columns: x => new { x.tenant_id, x.category_id },
+                        principalTable: "categories",
+                        principalColumns: new[] { "tenant_id", "id" },
+                        onDelete: ReferentialAction.Restrict);
+                    table.ForeignKey(
+                        name: "fk_content_assets_content_nodes_tenant_id_content_node_id",
+                        columns: x => new { x.tenant_id, x.content_node_id },
+                        principalTable: "content_nodes",
+                        principalColumns: new[] { "tenant_id", "id" },
+                        onDelete: ReferentialAction.Restrict);
+                    table.ForeignKey(
+                        name: "fk_content_assets_regions_tenant_id_region_id",
+                        columns: x => new { x.tenant_id, x.region_id },
+                        principalTable: "regions",
+                        principalColumns: new[] { "tenant_id", "id" },
+                        onDelete: ReferentialAction.Restrict);
+                    table.ForeignKey(
+                        name: "fk_content_assets_subjects_tenant_id_subject_id",
+                        columns: x => new { x.tenant_id, x.subject_id },
+                        principalTable: "subjects",
+                        principalColumns: new[] { "tenant_id", "id" },
+                        onDelete: ReferentialAction.Restrict);
+                    table.ForeignKey(
+                        name: "fk_content_assets_tenants_tenant_id",
+                        column: x => x.tenant_id,
+                        principalTable: "tenants",
+                        principalColumn: "id",
+                        onDelete: ReferentialAction.Cascade);
+                    table.ForeignKey(
+                        name: "fk_content_assets_users_created_by",
+                        column: x => x.created_by,
+                        principalTable: "users",
+                        principalColumn: "id",
+                        onDelete: ReferentialAction.SetNull);
+                    table.ForeignKey(
+                        name: "fk_content_assets_users_updated_by",
+                        column: x => x.updated_by,
+                        principalTable: "users",
+                        principalColumn: "id",
+                        onDelete: ReferentialAction.SetNull);
+                    table.ForeignKey(
+                        name: "fk_content_assets_users_verified_by",
+                        column: x => x.verified_by,
+                        principalTable: "users",
+                        principalColumn: "id",
+                        onDelete: ReferentialAction.SetNull);
+                });
+
+            migrationBuilder.CreateTable(
+                name: "content_import_jobs",
+                columns: table => new
+                {
+                    id = table.Column<Guid>(type: "uuid", nullable: false, defaultValueSql: "gen_random_uuid()"),
+                    created_by = table.Column<Guid>(type: "uuid", nullable: true),
+                    target_region_id = table.Column<Guid>(type: "uuid", nullable: true),
+                    target_subject_id = table.Column<Guid>(type: "uuid", nullable: true),
+                    target_category_id = table.Column<Guid>(type: "uuid", nullable: true),
+                    target_content_node_id = table.Column<Guid>(type: "uuid", nullable: true),
+                    target_question_bank_id = table.Column<Guid>(type: "uuid", nullable: true),
+                    import_type = table.Column<string>(type: "character varying(32)", maxLength: 32, nullable: false),
+                    source_format = table.Column<string>(type: "character varying(32)", maxLength: 32, nullable: false),
+                    status = table.Column<string>(type: "character varying(32)", maxLength: 32, nullable: false),
+                    source_name = table.Column<string>(type: "character varying(500)", maxLength: 500, nullable: true),
+                    source_hash = table.Column<string>(type: "character varying(128)", maxLength: 128, nullable: true),
+                    dry_run = table.Column<bool>(type: "boolean", nullable: false),
+                    total_count = table.Column<int>(type: "integer", nullable: false),
+                    valid_count = table.Column<int>(type: "integer", nullable: false),
+                    error_count = table.Column<int>(type: "integer", nullable: false),
+                    warning_count = table.Column<int>(type: "integer", nullable: false),
+                    inserted_count = table.Column<int>(type: "integer", nullable: false),
+                    updated_count = table.Column<int>(type: "integer", nullable: false),
+                    skipped_count = table.Column<int>(type: "integer", nullable: false),
+                    summary = table.Column<JsonElement>(type: "jsonb", nullable: false, defaultValueSql: "'{}'::jsonb"),
+                    raw_payload = table.Column<JsonElement>(type: "jsonb", nullable: false, defaultValueSql: "'[]'::jsonb"),
+                    normalized_payload = table.Column<JsonElement>(type: "jsonb", nullable: false, defaultValueSql: "'[]'::jsonb"),
+                    error_message = table.Column<string>(type: "text", nullable: true),
+                    started_at = table.Column<DateTimeOffset>(type: "timestamp with time zone", nullable: true),
+                    finished_at = table.Column<DateTimeOffset>(type: "timestamp with time zone", nullable: true),
+                    tenant_id = table.Column<Guid>(type: "uuid", nullable: false),
+                    created_at = table.Column<DateTimeOffset>(type: "timestamp with time zone", nullable: false, defaultValueSql: "now()"),
+                    updated_at = table.Column<DateTimeOffset>(type: "timestamp with time zone", nullable: false, defaultValueSql: "now()")
+                },
+                constraints: table =>
+                {
+                    table.PrimaryKey("pk_content_import_jobs", x => x.id);
+                    table.UniqueConstraint("ak_content_import_jobs_tenant_id_id", x => new { x.tenant_id, x.id });
+                    table.CheckConstraint("ck_content_import_jobs_counts", "total_count >= 0 and valid_count >= 0 and error_count >= 0 and warning_count >= 0 and inserted_count >= 0 and updated_count >= 0 and skipped_count >= 0");
+                    table.ForeignKey(
+                        name: "fk_content_import_jobs_categories_tenant_id_target_category_id",
+                        columns: x => new { x.tenant_id, x.target_category_id },
+                        principalTable: "categories",
+                        principalColumns: new[] { "tenant_id", "id" },
+                        onDelete: ReferentialAction.Restrict);
+                    table.ForeignKey(
+                        name: "fk_content_import_jobs_content_nodes_tenant_id_target_content_~",
+                        columns: x => new { x.tenant_id, x.target_content_node_id },
+                        principalTable: "content_nodes",
+                        principalColumns: new[] { "tenant_id", "id" },
+                        onDelete: ReferentialAction.Restrict);
+                    table.ForeignKey(
+                        name: "fk_content_import_jobs_question_banks_tenant_id_target_questio~",
+                        columns: x => new { x.tenant_id, x.target_question_bank_id },
+                        principalTable: "question_banks",
+                        principalColumns: new[] { "tenant_id", "id" },
+                        onDelete: ReferentialAction.Restrict);
+                    table.ForeignKey(
+                        name: "fk_content_import_jobs_regions_tenant_id_target_region_id",
+                        columns: x => new { x.tenant_id, x.target_region_id },
+                        principalTable: "regions",
+                        principalColumns: new[] { "tenant_id", "id" },
+                        onDelete: ReferentialAction.Restrict);
+                    table.ForeignKey(
+                        name: "fk_content_import_jobs_subjects_tenant_id_target_subject_id",
+                        columns: x => new { x.tenant_id, x.target_subject_id },
+                        principalTable: "subjects",
+                        principalColumns: new[] { "tenant_id", "id" },
+                        onDelete: ReferentialAction.Restrict);
+                    table.ForeignKey(
+                        name: "fk_content_import_jobs_tenants_tenant_id",
+                        column: x => x.tenant_id,
+                        principalTable: "tenants",
+                        principalColumn: "id",
+                        onDelete: ReferentialAction.Cascade);
+                    table.ForeignKey(
+                        name: "fk_content_import_jobs_users_created_by",
+                        column: x => x.created_by,
+                        principalTable: "users",
+                        principalColumn: "id",
+                        onDelete: ReferentialAction.SetNull);
+                });
+
+            migrationBuilder.CreateTable(
+                name: "images",
+                columns: table => new
+                {
+                    id = table.Column<Guid>(type: "uuid", nullable: false, defaultValueSql: "gen_random_uuid()"),
+                    legacy_id = table.Column<string>(type: "character varying(64)", maxLength: 64, nullable: true),
+                    title = table.Column<string>(type: "character varying(300)", maxLength: 300, nullable: true),
+                    category = table.Column<string>(type: "character varying(100)", maxLength: 100, nullable: true),
+                    file_name = table.Column<string>(type: "character varying(500)", maxLength: 500, nullable: true),
+                    is_public = table.Column<bool>(type: "boolean", nullable: false),
+                    cdn_url = table.Column<string>(type: "character varying(2048)", maxLength: 2048, nullable: true),
+                    metadata = table.Column<JsonElement>(type: "jsonb", nullable: false, defaultValueSql: "'{}'::jsonb"),
+                    tenant_id = table.Column<Guid>(type: "uuid", nullable: false),
+                    created_at = table.Column<DateTimeOffset>(type: "timestamp with time zone", nullable: false, defaultValueSql: "now()"),
+                    updated_at = table.Column<DateTimeOffset>(type: "timestamp with time zone", nullable: false, defaultValueSql: "now()")
+                },
+                constraints: table =>
+                {
+                    table.PrimaryKey("pk_images", x => x.id);
+                    table.UniqueConstraint("ak_images_tenant_id_id", x => new { x.tenant_id, x.id });
+                    table.ForeignKey(
+                        name: "fk_images_tenants_tenant_id",
+                        column: x => x.tenant_id,
+                        principalTable: "tenants",
+                        principalColumn: "id",
+                        onDelete: ReferentialAction.Cascade);
+                });
+
+            migrationBuilder.CreateTable(
+                name: "video_explanations",
+                columns: table => new
+                {
+                    id = table.Column<Guid>(type: "uuid", nullable: false, defaultValueSql: "gen_random_uuid()"),
+                    subject_id = table.Column<Guid>(type: "uuid", nullable: true),
+                    legacy_id = table.Column<string>(type: "character varying(64)", maxLength: 64, nullable: true),
+                    legacy_subject_id = table.Column<string>(type: "character varying(64)", maxLength: 64, nullable: true),
+                    title = table.Column<string>(type: "character varying(300)", maxLength: 300, nullable: false),
+                    description = table.Column<string>(type: "text", nullable: true),
+                    video_url = table.Column<string>(type: "character varying(2048)", maxLength: 2048, nullable: true),
+                    thumbnail_url = table.Column<string>(type: "character varying(2048)", maxLength: 2048, nullable: true),
+                    duration_seconds = table.Column<int>(type: "integer", nullable: true),
+                    knowledge_tags = table.Column<JsonElement>(type: "jsonb", nullable: false, defaultValueSql: "'[]'::jsonb"),
+                    is_general = table.Column<bool>(type: "boolean", nullable: false),
+                    difficulty = table.Column<int>(type: "integer", nullable: true),
+                    sort_order = table.Column<int>(type: "integer", nullable: false),
+                    is_active = table.Column<bool>(type: "boolean", nullable: false),
+                    source_hash = table.Column<string>(type: "character varying(128)", maxLength: 128, nullable: true),
+                    metadata = table.Column<JsonElement>(type: "jsonb", nullable: false, defaultValueSql: "'{}'::jsonb"),
+                    tenant_id = table.Column<Guid>(type: "uuid", nullable: false),
+                    created_at = table.Column<DateTimeOffset>(type: "timestamp with time zone", nullable: false, defaultValueSql: "now()"),
+                    updated_at = table.Column<DateTimeOffset>(type: "timestamp with time zone", nullable: false, defaultValueSql: "now()")
+                },
+                constraints: table =>
+                {
+                    table.PrimaryKey("pk_video_explanations", x => x.id);
+                    table.UniqueConstraint("ak_video_explanations_tenant_id_id", x => new { x.tenant_id, x.id });
+                    table.ForeignKey(
+                        name: "fk_video_explanations_subjects_tenant_id_subject_id",
+                        columns: x => new { x.tenant_id, x.subject_id },
+                        principalTable: "subjects",
+                        principalColumns: new[] { "tenant_id", "id" },
+                        onDelete: ReferentialAction.Restrict);
+                    table.ForeignKey(
+                        name: "fk_video_explanations_tenants_tenant_id",
+                        column: x => x.tenant_id,
+                        principalTable: "tenants",
+                        principalColumn: "id",
+                        onDelete: ReferentialAction.Cascade);
+                });
+
+            migrationBuilder.CreateTable(
+                name: "content_import_items",
+                columns: table => new
+                {
+                    id = table.Column<Guid>(type: "uuid", nullable: false, defaultValueSql: "gen_random_uuid()"),
+                    job_id = table.Column<Guid>(type: "uuid", nullable: false),
+                    row_no = table.Column<int>(type: "integer", nullable: false),
+                    external_id = table.Column<string>(type: "character varying(200)", maxLength: 200, nullable: true),
+                    status = table.Column<string>(type: "character varying(32)", maxLength: 32, nullable: false),
+                    target_type = table.Column<string>(type: "character varying(100)", maxLength: 100, nullable: true),
+                    target_id = table.Column<Guid>(type: "uuid", nullable: true),
+                    source_payload = table.Column<JsonElement>(type: "jsonb", nullable: false, defaultValueSql: "'{}'::jsonb"),
+                    normalized_payload = table.Column<JsonElement>(type: "jsonb", nullable: false, defaultValueSql: "'{}'::jsonb"),
+                    content_hash = table.Column<string>(type: "character varying(128)", maxLength: 128, nullable: true),
+                    issues_count = table.Column<int>(type: "integer", nullable: false),
+                    tenant_id = table.Column<Guid>(type: "uuid", nullable: false),
+                    created_at = table.Column<DateTimeOffset>(type: "timestamp with time zone", nullable: false, defaultValueSql: "now()"),
+                    updated_at = table.Column<DateTimeOffset>(type: "timestamp with time zone", nullable: false, defaultValueSql: "now()")
+                },
+                constraints: table =>
+                {
+                    table.PrimaryKey("pk_content_import_items", x => x.id);
+                    table.UniqueConstraint("ak_content_import_items_tenant_id_id", x => new { x.tenant_id, x.id });
+                    table.CheckConstraint("ck_content_import_items_issues_count", "issues_count >= 0");
+                    table.CheckConstraint("ck_content_import_items_row_no", "row_no >= 0");
+                    table.ForeignKey(
+                        name: "fk_content_import_items_content_import_jobs_tenant_id_job_id",
+                        columns: x => new { x.tenant_id, x.job_id },
+                        principalTable: "content_import_jobs",
+                        principalColumns: new[] { "tenant_id", "id" },
+                        onDelete: ReferentialAction.Cascade);
+                    table.ForeignKey(
+                        name: "fk_content_import_items_tenants_tenant_id",
+                        column: x => x.tenant_id,
+                        principalTable: "tenants",
+                        principalColumn: "id",
+                        onDelete: ReferentialAction.Cascade);
+                });
+
+            migrationBuilder.CreateTable(
+                name: "question_videos",
+                columns: table => new
+                {
+                    id = table.Column<Guid>(type: "uuid", nullable: false, defaultValueSql: "gen_random_uuid()"),
+                    question_id = table.Column<Guid>(type: "uuid", nullable: true),
+                    video_id = table.Column<Guid>(type: "uuid", nullable: true),
+                    legacy_id = table.Column<string>(type: "character varying(64)", maxLength: 64, nullable: true),
+                    legacy_question_id = table.Column<string>(type: "character varying(64)", maxLength: 64, nullable: true),
+                    legacy_video_id = table.Column<string>(type: "character varying(64)", maxLength: 64, nullable: true),
+                    video_type = table.Column<string>(type: "character varying(32)", maxLength: 32, nullable: false),
+                    sort_order = table.Column<int>(type: "integer", nullable: false),
+                    metadata = table.Column<JsonElement>(type: "jsonb", nullable: false, defaultValueSql: "'{}'::jsonb"),
+                    tenant_id = table.Column<Guid>(type: "uuid", nullable: false),
+                    created_at = table.Column<DateTimeOffset>(type: "timestamp with time zone", nullable: false, defaultValueSql: "now()"),
+                    updated_at = table.Column<DateTimeOffset>(type: "timestamp with time zone", nullable: false, defaultValueSql: "now()")
+                },
+                constraints: table =>
+                {
+                    table.PrimaryKey("pk_question_videos", x => x.id);
+                    table.UniqueConstraint("ak_question_videos_tenant_id_id", x => new { x.tenant_id, x.id });
+                    table.ForeignKey(
+                        name: "fk_question_videos_questions_tenant_id_question_id",
+                        columns: x => new { x.tenant_id, x.question_id },
+                        principalTable: "questions",
+                        principalColumns: new[] { "tenant_id", "id" },
+                        onDelete: ReferentialAction.Cascade);
+                    table.ForeignKey(
+                        name: "fk_question_videos_tenants_tenant_id",
+                        column: x => x.tenant_id,
+                        principalTable: "tenants",
+                        principalColumn: "id",
+                        onDelete: ReferentialAction.Cascade);
+                    table.ForeignKey(
+                        name: "fk_question_videos_video_explanations_tenant_id_video_id",
+                        columns: x => new { x.tenant_id, x.video_id },
+                        principalTable: "video_explanations",
+                        principalColumns: new[] { "tenant_id", "id" },
+                        onDelete: ReferentialAction.Cascade);
+                });
+
+            migrationBuilder.CreateTable(
+                name: "content_import_issues",
+                columns: table => new
+                {
+                    id = table.Column<Guid>(type: "uuid", nullable: false, defaultValueSql: "gen_random_uuid()"),
+                    job_id = table.Column<Guid>(type: "uuid", nullable: false),
+                    item_id = table.Column<Guid>(type: "uuid", nullable: true),
+                    row_no = table.Column<int>(type: "integer", nullable: true),
+                    severity = table.Column<string>(type: "character varying(32)", maxLength: 32, nullable: false),
+                    code = table.Column<string>(type: "character varying(100)", maxLength: 100, nullable: false),
+                    field_path = table.Column<string>(type: "character varying(500)", maxLength: 500, nullable: true),
+                    message = table.Column<string>(type: "character varying(2000)", maxLength: 2000, nullable: false),
+                    details = table.Column<JsonElement>(type: "jsonb", nullable: false, defaultValueSql: "'{}'::jsonb"),
+                    tenant_id = table.Column<Guid>(type: "uuid", nullable: false),
+                    created_at = table.Column<DateTimeOffset>(type: "timestamp with time zone", nullable: false, defaultValueSql: "now()"),
+                    updated_at = table.Column<DateTimeOffset>(type: "timestamp with time zone", nullable: false, defaultValueSql: "now()")
+                },
+                constraints: table =>
+                {
+                    table.PrimaryKey("pk_content_import_issues", x => x.id);
+                    table.UniqueConstraint("ak_content_import_issues_tenant_id_id", x => new { x.tenant_id, x.id });
+                    table.ForeignKey(
+                        name: "fk_content_import_issues_content_import_items_tenant_id_item_id",
+                        columns: x => new { x.tenant_id, x.item_id },
+                        principalTable: "content_import_items",
+                        principalColumns: new[] { "tenant_id", "id" },
+                        onDelete: ReferentialAction.Cascade);
+                    table.ForeignKey(
+                        name: "fk_content_import_issues_content_import_jobs_tenant_id_job_id",
+                        columns: x => new { x.tenant_id, x.job_id },
+                        principalTable: "content_import_jobs",
+                        principalColumns: new[] { "tenant_id", "id" },
+                        onDelete: ReferentialAction.Cascade);
+                    table.ForeignKey(
+                        name: "fk_content_import_issues_tenants_tenant_id",
+                        column: x => x.tenant_id,
+                        principalTable: "tenants",
+                        principalColumn: "id",
+                        onDelete: ReferentialAction.Cascade);
+                });
+
+            migrationBuilder.CreateIndex(
+                name: "ix_app_assets_tenant_id_asset_key",
+                table: "app_assets",
+                columns: new[] { "tenant_id", "asset_key" },
+                unique: true);
+
+            migrationBuilder.CreateIndex(
+                name: "ix_app_assets_tenant_id_legacy_id",
+                table: "app_assets",
+                columns: new[] { "tenant_id", "legacy_id" },
+                unique: true);
+
+            migrationBuilder.CreateIndex(
+                name: "ix_content_assets_created_by",
+                table: "content_assets",
+                column: "created_by");
+
+            migrationBuilder.CreateIndex(
+                name: "ix_content_assets_tenant_id_category_id",
+                table: "content_assets",
+                columns: new[] { "tenant_id", "category_id" });
+
+            migrationBuilder.CreateIndex(
+                name: "ix_content_assets_tenant_id_checksum_sha256",
+                table: "content_assets",
+                columns: new[] { "tenant_id", "checksum_sha256" },
+                filter: "checksum_sha256 is not null");
+
+            migrationBuilder.CreateIndex(
+                name: "ix_content_assets_tenant_id_content_node_id",
+                table: "content_assets",
+                columns: new[] { "tenant_id", "content_node_id" });
+
+            migrationBuilder.CreateIndex(
+                name: "ix_content_assets_tenant_id_legacy_id",
+                table: "content_assets",
+                columns: new[] { "tenant_id", "legacy_id" },
+                unique: true);
+
+            migrationBuilder.CreateIndex(
+                name: "ix_content_assets_tenant_id_preview_status",
+                table: "content_assets",
+                columns: new[] { "tenant_id", "preview_status" },
+                filter: "preview_status <> 'none'");
+
+            migrationBuilder.CreateIndex(
+                name: "ix_content_assets_tenant_id_region_id",
+                table: "content_assets",
+                columns: new[] { "tenant_id", "region_id" });
+
+            migrationBuilder.CreateIndex(
+                name: "ix_content_assets_tenant_id_status_visibility_asset_type_regio~",
+                table: "content_assets",
+                columns: new[] { "tenant_id", "status", "visibility", "asset_type", "region_id", "subject_id", "category_id", "sort_order" });
+
+            migrationBuilder.CreateIndex(
+                name: "ix_content_assets_tenant_id_storage_provider_bucket_object_key",
+                table: "content_assets",
+                columns: new[] { "tenant_id", "storage_provider", "bucket", "object_key" });
+
+            migrationBuilder.CreateIndex(
+                name: "ix_content_assets_tenant_id_subject_id",
+                table: "content_assets",
+                columns: new[] { "tenant_id", "subject_id" });
+
+            migrationBuilder.CreateIndex(
+                name: "ix_content_assets_tenant_id_upload_status_status_updated_at",
+                table: "content_assets",
+                columns: new[] { "tenant_id", "upload_status", "status", "updated_at" });
+
+            migrationBuilder.CreateIndex(
+                name: "ix_content_assets_updated_by",
+                table: "content_assets",
+                column: "updated_by");
+
+            migrationBuilder.CreateIndex(
+                name: "ix_content_assets_verified_by",
+                table: "content_assets",
+                column: "verified_by");
+
+            migrationBuilder.CreateIndex(
+                name: "ix_content_import_issues_tenant_id_item_id",
+                table: "content_import_issues",
+                columns: new[] { "tenant_id", "item_id" });
+
+            migrationBuilder.CreateIndex(
+                name: "ix_content_import_issues_tenant_id_job_id_severity_row_no",
+                table: "content_import_issues",
+                columns: new[] { "tenant_id", "job_id", "severity", "row_no" });
+
+            migrationBuilder.CreateIndex(
+                name: "ix_content_import_items_job_id_row_no",
+                table: "content_import_items",
+                columns: new[] { "job_id", "row_no" },
+                unique: true);
+
+            migrationBuilder.CreateIndex(
+                name: "ix_content_import_items_tenant_id_job_id_status_row_no",
+                table: "content_import_items",
+                columns: new[] { "tenant_id", "job_id", "status", "row_no" });
+
+            migrationBuilder.CreateIndex(
+                name: "ix_content_import_jobs_created_by",
+                table: "content_import_jobs",
+                column: "created_by");
+
+            migrationBuilder.CreateIndex(
+                name: "ix_content_import_jobs_tenant_id_import_type_status_created_at",
+                table: "content_import_jobs",
+                columns: new[] { "tenant_id", "import_type", "status", "created_at" });
+
+            migrationBuilder.CreateIndex(
+                name: "ix_content_import_jobs_tenant_id_target_category_id",
+                table: "content_import_jobs",
+                columns: new[] { "tenant_id", "target_category_id" });
+
+            migrationBuilder.CreateIndex(
+                name: "ix_content_import_jobs_tenant_id_target_content_node_id",
+                table: "content_import_jobs",
+                columns: new[] { "tenant_id", "target_content_node_id" });
+
+            migrationBuilder.CreateIndex(
+                name: "ix_content_import_jobs_tenant_id_target_question_bank_id",
+                table: "content_import_jobs",
+                columns: new[] { "tenant_id", "target_question_bank_id" });
+
+            migrationBuilder.CreateIndex(
+                name: "ix_content_import_jobs_tenant_id_target_region_id",
+                table: "content_import_jobs",
+                columns: new[] { "tenant_id", "target_region_id" });
+
+            migrationBuilder.CreateIndex(
+                name: "ix_content_import_jobs_tenant_id_target_subject_id",
+                table: "content_import_jobs",
+                columns: new[] { "tenant_id", "target_subject_id" });
+
+            migrationBuilder.CreateIndex(
+                name: "ix_images_tenant_id_category_is_public",
+                table: "images",
+                columns: new[] { "tenant_id", "category", "is_public" });
+
+            migrationBuilder.CreateIndex(
+                name: "ix_images_tenant_id_legacy_id",
+                table: "images",
+                columns: new[] { "tenant_id", "legacy_id" },
+                unique: true);
+
+            migrationBuilder.CreateIndex(
+                name: "ix_question_videos_tenant_id_legacy_id",
+                table: "question_videos",
+                columns: new[] { "tenant_id", "legacy_id" },
+                unique: true);
+
+            migrationBuilder.CreateIndex(
+                name: "ix_question_videos_tenant_id_question_id_video_id_video_type",
+                table: "question_videos",
+                columns: new[] { "tenant_id", "question_id", "video_id", "video_type" },
+                unique: true);
+
+            migrationBuilder.CreateIndex(
+                name: "ix_question_videos_tenant_id_video_id",
+                table: "question_videos",
+                columns: new[] { "tenant_id", "video_id" });
+
+            migrationBuilder.CreateIndex(
+                name: "ix_video_explanations_tenant_id_legacy_id",
+                table: "video_explanations",
+                columns: new[] { "tenant_id", "legacy_id" },
+                unique: true);
+
+            migrationBuilder.CreateIndex(
+                name: "ix_video_explanations_tenant_id_source_hash",
+                table: "video_explanations",
+                columns: new[] { "tenant_id", "source_hash" },
+                filter: "source_hash is not null");
+
+            migrationBuilder.CreateIndex(
+                name: "ix_video_explanations_tenant_id_subject_id_is_active_sort_order",
+                table: "video_explanations",
+                columns: new[] { "tenant_id", "subject_id", "is_active", "sort_order" });
+        }
+
+        /// <inheritdoc />
+        protected override void Down(MigrationBuilder migrationBuilder)
+        {
+            migrationBuilder.DropTable(
+                name: "app_assets");
+
+            migrationBuilder.DropTable(
+                name: "content_assets");
+
+            migrationBuilder.DropTable(
+                name: "content_import_issues");
+
+            migrationBuilder.DropTable(
+                name: "images");
+
+            migrationBuilder.DropTable(
+                name: "question_videos");
+
+            migrationBuilder.DropTable(
+                name: "content_import_items");
+
+            migrationBuilder.DropTable(
+                name: "video_explanations");
+
+            migrationBuilder.DropTable(
+                name: "content_import_jobs");
+        }
+    }
+}

Tiku.Infrastructure/Persistence/TikuDbContext.cs

@@ -43,6 +43,14 @@ public sealed class TikuDbContext(DbContextOptions<TikuDbContext> options) : DbC
     public DbSet<HandbookEntry> HandbookEntries => Set<HandbookEntry>();
     public DbSet<QuestionTypeGroup> QuestionTypeGroups => Set<QuestionTypeGroup>();
     public DbSet<SubjectShare> SubjectShares => Set<SubjectShare>();
+    public DbSet<ContentAsset> ContentAssets => Set<ContentAsset>();
+    public DbSet<ContentImportJob> ContentImportJobs => Set<ContentImportJob>();
+    public DbSet<ContentImportItem> ContentImportItems => Set<ContentImportItem>();
+    public DbSet<ContentImportIssue> ContentImportIssues => Set<ContentImportIssue>();
+    public DbSet<ImageAsset> Images => Set<ImageAsset>();
+    public DbSet<AppAsset> AppAssets => Set<AppAsset>();
+    public DbSet<VideoExplanation> VideoExplanations => Set<VideoExplanation>();
+    public DbSet<QuestionVideo> QuestionVideos => Set<QuestionVideo>();
     public DbSet<PracticeSession> PracticeSessions => Set<PracticeSession>();
     public DbSet<AnswerRecord> AnswerRecords => Set<AnswerRecord>();
     public DbSet<FavoriteQuestion> FavoriteQuestions => Set<FavoriteQuestion>();

Tiku.IntegrationTests/PersistenceModelTests.cs

@@ -23,7 +23,7 @@ public sealed class PersistenceModelTests
             .Select(entity => entity.GetTableName())
             .ToHashSet(StringComparer.Ordinal);
 
-        Assert.Equal(37, tableNames.Count);
+        Assert.Equal(45, tableNames.Count);
         Assert.Contains("tenants", tableNames);
         Assert.Contains("tenant_settings", tableNames);
         Assert.Contains("content_entries", tableNames);
@@ -39,6 +39,14 @@ public sealed class PersistenceModelTests
         Assert.Contains("handbook_entries", tableNames);
         Assert.Contains("question_type_groups", tableNames);
         Assert.Contains("subject_shares", tableNames);
+        Assert.Contains("content_assets", tableNames);
+        Assert.Contains("content_import_jobs", tableNames);
+        Assert.Contains("content_import_items", tableNames);
+        Assert.Contains("content_import_issues", tableNames);
+        Assert.Contains("images", tableNames);
+        Assert.Contains("app_assets", tableNames);
+        Assert.Contains("video_explanations", tableNames);
+        Assert.Contains("question_videos", tableNames);
         Assert.Contains("questions", tableNames);
         Assert.Contains("question_versions", tableNames);
         Assert.Contains("answer_records", tableNames);
@@ -209,4 +217,83 @@ public sealed class PersistenceModelTests
                         .SequenceEqual(propertyNames));
         }
     }
+
+    [Theory]
+    [InlineData(typeof(ContentAsset), nameof(ContentAsset.AccessRules), "'{}'::jsonb")]
+    [InlineData(typeof(ContentAsset), nameof(ContentAsset.VerificationDetails), "'{}'::jsonb")]
+    [InlineData(typeof(ContentAsset), nameof(ContentAsset.SecurityFlags), "'{}'::jsonb")]
+    [InlineData(typeof(ContentImportJob), nameof(ContentImportJob.RawPayload), "'[]'::jsonb")]
+    [InlineData(typeof(ContentImportItem), nameof(ContentImportItem.SourcePayload), "'{}'::jsonb")]
+    [InlineData(typeof(ContentImportIssue), nameof(ContentImportIssue.Details), "'{}'::jsonb")]
+    [InlineData(typeof(VideoExplanation), nameof(VideoExplanation.KnowledgeTags), "'[]'::jsonb")]
+    [InlineData(typeof(QuestionVideo), nameof(QuestionVideo.Metadata), "'{}'::jsonb")]
+    public void Asset_import_and_video_json_properties_are_mapped_to_jsonb(
+        Type entityType,
+        string propertyName,
+        string expectedDefaultValueSql)
+    {
+        using var context = new TikuDbContext(Options);
+
+        var property = context.Model.FindEntityType(entityType)!
+            .FindProperty(propertyName)!;
+
+        Assert.Equal("jsonb", property.GetColumnType());
+        Assert.Equal(expectedDefaultValueSql, property.GetDefaultValueSql());
+        Assert.Equal(typeof(System.Text.Json.JsonElement), property.ClrType);
+    }
+
+    [Fact]
+    public void Import_items_and_question_videos_have_expected_unique_indexes()
+    {
+        using var context = new TikuDbContext(Options);
+
+        AssertHasUniqueIndex<ContentImportItem>(
+            nameof(ContentImportItem.JobId),
+            nameof(ContentImportItem.RowNo));
+        AssertHasUniqueIndex<QuestionVideo>(
+            nameof(QuestionVideo.TenantId),
+            nameof(QuestionVideo.QuestionId),
+            nameof(QuestionVideo.VideoId),
+            nameof(QuestionVideo.VideoType));
+
+        void AssertHasUniqueIndex<TEntity>(params string[] propertyNames)
+        {
+            var indexes = context.Model.FindEntityType(typeof(TEntity))!.GetIndexes();
+
+            Assert.Contains(
+                indexes,
+                index => index.IsUnique
+                    && index.Properties
+                        .Select(property => property.Name)
+                        .SequenceEqual(propertyNames));
+        }
+    }
+
+    [Fact]
+    public void Asset_import_and_video_relations_include_tenant_in_foreign_keys()
+    {
+        using var context = new TikuDbContext(Options);
+
+        var entityTypes = new[]
+        {
+            typeof(ContentAsset),
+            typeof(ContentImportJob),
+            typeof(ContentImportItem),
+            typeof(ContentImportIssue),
+            typeof(VideoExplanation),
+            typeof(QuestionVideo)
+        };
+
+        var compositeForeignKeys = entityTypes
+            .SelectMany(entityType => context.Model.FindEntityType(entityType)!
+                .GetForeignKeys())
+            .Where(foreignKey => foreignKey.Properties.Count > 1)
+            .Select(foreignKey => foreignKey.Properties
+                .Select(property => property.Name)
+                .ToArray());
+
+        Assert.All(
+            compositeForeignKeys,
+            properties => Assert.Contains("TenantId", properties));
+    }
 }