Phase 11: version PDF (FR-15)

- เลข version ใหม่: เว็บ-generate = v0 ฉบับตั้งต้น (ไม่มี PDF), add-in save (Start Versioning + Save & Version) = v1+ มี PDF เสมอ
- PDF ผลิตจาก Word จริงผ่าน task pane เท่านั้น (getFileAsync Pdf + runtime guard, manifest ไม่เพิ่ม requirement); capture/upload เป็น best-effort — docx ผ่านแม้ PDF ล้ม + MessageBar เตือนตาม hasPdf
- Backend: DocumentVersion.PdfObjectKey (nullable, migration AddVersionPdf) + sibling .pdf ใน bucket docx-versions · multipart part pdf (ผิด type → 400) · /download + /download-link รับ ?format=pdf (ไม่มี → 404) · presigned ฝังชื่อไฟล์ไทย + _vN (RFC 5987)
- Web: เปิดไฟล์แทน blob-download — PDF แท็บใหม่, docx ผ่าน ms-word:ofe|u| พร้อม heuristic fallback ลิงก์สำรอง (useVersionOpen, versionDownload) · ปุ่ม "เปิดใน Word" ที่หน้า success ของฟอร์มสร้างเอกสาร
- Spec v7 + CONTEXT.md + ADR 0001 + แผน docs/plans/version-pdf.md
- Automated QA: backend 68 / add-in 63 / web 55 ผ่าน · manual acceptance ผ่านบน Word for Mac (2026-09-08) รวม fidelity + track changes — ค้างเฉพาะ Windows / Word on the web

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

backend/WordVersioning.Api/Controllers/DocumentsController.cs

@@ -37,6 +37,7 @@ public class DocumentsController(
     private const int MaxVersionMessageLength = 2048; // FR-13 — ตรงกับ HasMaxLength ใน AppDbContext
 
     /// <summary>FR-5 — อัปโหลด version ใหม่ (auto-create Document ถ้ายังไม่มี)
+    /// + FR-15: optional PDF; PDF storage failure still returns 201 with HasPdf=false
     /// + FR-11: แนบ `fields` (map tag→text) → sync latest values + snapshot ต่อ version</summary>
     [HttpPost("{documentId:guid}/versions")]
     [RequestSizeLimit(MaxUploadBytes)]
@@ -65,6 +66,21 @@ public class DocumentsController(
         if (message is { Length: > MaxVersionMessageLength })
             return BadRequest($"`message` ยาวเกิน {MaxVersionMessageLength} อักขระ");
 
+        if (request.Pdf is not null)
+        {
+            if (request.Pdf.Length > MaxUploadBytes)
+                return StatusCode(StatusCodes.Status413PayloadTooLarge, "ไฟล์ PDF ใหญ่เกิน 100MB");
+            if (request.Pdf.Length == 0 || !PdfUploadValidation.IsValidPdf(request.Pdf))
+                return BadRequest("ต้องแนบไฟล์ .pdf ที่ไม่ว่าง (application/pdf)");
+        }
+
+        await using var pdfStream = new MemoryStream();
+        if (request.Pdf is not null)
+        {
+            await request.Pdf.CopyToAsync(pdfStream, ct);
+            pdfStream.Position = 0;
+        }
+
         var now = DateTimeOffset.UtcNow;
         var fileName = request.File.FileName;
 
@@ -133,6 +149,7 @@ public class DocumentsController(
                 DocumentId = documentId,
                 VersionNumber = nextNumber,
                 ObjectKey = $"{documentId}/v{nextNumber:D4}_{request.ClientVersionId}.docx",
+                PdfObjectKey = request.Pdf is null ? null : $"{documentId}/v{nextNumber:D4}_{request.ClientVersionId}.pdf",
                 ContentHash = contentHash,
                 CreatedByUserId = currentUser.UserId, // จาก claim `sub` เท่านั้น
                 CreatedAt = now,
@@ -187,15 +204,31 @@ public class DocumentsController(
             return StatusCode(StatusCodes.Status502BadGateway, "อัปโหลดไฟล์ขึ้น storage ไม่สำเร็จ");
         }
 
+        // FR-15: PDF is derived; its storage failure must not undo the saved docx.
+        if (version.PdfObjectKey is not null)
+        {
+            try
+            {
+                await storage.PutAsync(minioOptions.Value.VersionsBucket, version.PdfObjectKey,
+                    pdfStream, PdfUploadValidation.PdfContentType, ct);
+            }
+            catch (Exception ex) when (ex is AmazonServiceException or IOException or HttpRequestException or OperationCanceledException)
+            {
+                logger.LogWarning(ex, "PDF upload failed documentId={DocumentId} versionId={VersionId}", documentId, version.Id);
+                version.PdfObjectKey = null;
+                await db.SaveChangesAsync(CancellationToken.None);
+            }
+        }
+
         logger.LogInformation(
             "Version uploaded documentId={DocumentId} versionId={VersionId} versionNumber={VersionNumber} userId={UserId} bytes={Size} hash={Hash}",
             documentId, version.Id, version.VersionNumber, currentUser.UserId, request.File.Length, contentHash);
 
         return CreatedAtAction(nameof(GetVersions), new { documentId },
-            new UploadVersionResponse(version.Id, version.VersionNumber));
+            new UploadVersionResponse(version.Id, version.VersionNumber, version.PdfObjectKey is not null));
     }
 
-    /// <summary>FR-10 — สร้างเอกสารจาก template: generate docx + stamp metadata + upload version 1
+    /// <summary>FR-10 — สร้างเอกสารจาก template: generate docx + stamp metadata + upload version 0
     /// + field values ทั้งหมดใน flow เดียว — เปิดใน Word แล้ว add-in ตรวจพบ tracked document ทันที (AC-12)</summary>
     [HttpPost("generate")]
     [ProducesResponseType(typeof(GenerateDocumentResponse), StatusCodes.Status201Created)]
@@ -304,8 +337,8 @@ public class DocumentsController(
             {
                 Id = Guid.NewGuid(),
                 DocumentId = documentId,
-                VersionNumber = 1,
-                ObjectKey = $"{documentId}/v0001_{Guid.NewGuid()}.docx", // clientVersionId generate ฝั่ง server (flow นี้ไม่มี client)
+                VersionNumber = 0,
+                ObjectKey = $"{documentId}/v0000_{Guid.NewGuid()}.docx", // clientVersionId generate ฝั่ง server (flow นี้ไม่มี client)
                 ContentHash = contentHash,
                 CreatedByUserId = currentUser.UserId,
                 CreatedAt = now,
@@ -313,7 +346,7 @@ public class DocumentsController(
             };
             db.DocumentVersions.Add(version);
 
-            // snapshot + field values ของ v1 (ทุก field มีค่า = missing=false ทั้งหมด)
+            // snapshot + field values ของ v0 (ทุก field มีค่า = missing=false ทั้งหมด)
             var sync = await fieldSync.StageFieldSyncAsync(doc, version.Id, values, now, ct);
             version.FieldsSnapshotJson = sync.SnapshotJson;
 
@@ -434,37 +467,43 @@ public class DocumentsController(
                 v.ContentHash,
                 v.FieldsSnapshotJson,
                 v.Message,
+                v.PdfObjectKey,
             })
             .ToListAsync(ct);
 
         return Ok(rows.Select(r => new VersionListItem(
             r.Id, r.VersionNumber, r.CreatedAt, r.CreatedByUserId, r.ContentHash,
-            ParseSnapshot(r.FieldsSnapshotJson), r.Message)).ToList());
+            ParseSnapshot(r.FieldsSnapshotJson), r.Message, r.PdfObjectKey is not null)).ToList());
     }
 
-    /// <summary>FR-7 — ดาวน์โหลด version ที่ระบุ (proxy stream จาก MinIO — ไม่ expose MinIO ตรงๆ)</summary>
+    /// <summary>FR-7/FR-15 — proxy download; format=pdf selects PDF (404 when absent), default is docx.</summary>
     [HttpGet("{documentId:guid}/versions/{versionId:guid}/download")]
     [ProducesResponseType(typeof(FileContentResult), StatusCodes.Status200OK)]
     [ProducesResponseType(StatusCodes.Status404NotFound)]
-    public async Task<IActionResult> DownloadVersion(Guid documentId, Guid versionId, CancellationToken ct)
+    public async Task<IActionResult> DownloadVersion(Guid documentId, Guid versionId, CancellationToken ct, [FromQuery] string? format = null)
     {
         var row = await db.DocumentVersions
             .AsNoTracking()
             .Where(v => v.DocumentId == documentId && v.Id == versionId)
-            .Join(db.Documents, v => v.DocumentId, d => d.Id, (v, d) => new { v.ObjectKey, d.FileName })
+            .Join(db.Documents, v => v.DocumentId, d => d.Id, (v, d) => new { v.ObjectKey, v.PdfObjectKey, d.FileName })
             .FirstOrDefaultAsync(ct);
         if (row is null)
             return NotFound($"ไม่พบ version {versionId} ของ document {documentId}");
 
+        var isPdf = string.Equals(format, "pdf", StringComparison.OrdinalIgnoreCase);
+        var objectKey = isPdf ? row.PdfObjectKey : row.ObjectKey;
+        if (objectKey is null)
+            return NotFound("version นี้ไม่มีสำเนา PDF");
+
         Stream stream;
         try
         {
-            stream = await storage.GetStreamAsync(minioOptions.Value.VersionsBucket, row.ObjectKey, ct);
+            stream = await storage.GetStreamAsync(minioOptions.Value.VersionsBucket, objectKey, ct);
         }
         catch (KeyNotFoundException)
         {
             logger.LogError("Object missing in storage documentId={DocumentId} versionId={VersionId} key={ObjectKey}",
-                documentId, versionId, row.ObjectKey);
+                documentId, versionId, objectKey);
             return NotFound("ไฟล์ของ version นี้ไม่พบใน storage");
         }
 
@@ -474,28 +513,38 @@ public class DocumentsController(
         var downloadName = row.FileName.EndsWith(".docx", StringComparison.OrdinalIgnoreCase)
             ? row.FileName
             : row.FileName + ".docx";
-        return File(stream, DocxContentType, downloadName);
+        return File(stream, isPdf ? PdfUploadValidation.PdfContentType : DocxContentType,
+            isPdf ? Path.ChangeExtension(downloadName, ".pdf") : downloadName);
     }
 
-    /// <summary>FR-7 (ทางเลือก presigned URL อายุสั้น — spec ส่วน 9 อนุญาต)
+    /// <summary>FR-7/FR-15 — presigned URL with filename; format=pdf selects inline PDF (404 when absent).
     /// ออก URL ให้ add-in เปิดในเบราว์เซอร์ของผู้ใช้โดยตรง — webview ของ Word (โดยเฉพาะ WKWebView บน Mac)
     /// ทิ้ง blob download แบบเงียบๆ จึงต้องให้เบราว์เซอร์จริงจัดการการดาวน์โหลดแทน</summary>
     [HttpGet("{documentId:guid}/versions/{versionId:guid}/download-link")]
     [ProducesResponseType(typeof(VersionDownloadLinkResponse), StatusCodes.Status200OK)]
     [ProducesResponseType(StatusCodes.Status404NotFound)]
     public async Task<ActionResult<VersionDownloadLinkResponse>> GetVersionDownloadLink(
-        Guid documentId, Guid versionId, CancellationToken ct)
+        Guid documentId, Guid versionId, CancellationToken ct, [FromQuery] string? format = null)
     {
-        var objectKey = await db.DocumentVersions
+        var row = await db.DocumentVersions
             .AsNoTracking()
             .Where(v => v.DocumentId == documentId && v.Id == versionId)
-            .Select(v => v.ObjectKey)
+            .Join(db.Documents, v => v.DocumentId, d => d.Id,
+                (v, d) => new { v.ObjectKey, v.PdfObjectKey, v.VersionNumber, d.FileName })
             .FirstOrDefaultAsync(ct);
-        if (objectKey is null)
+        if (row is null)
             return NotFound($"ไม่พบ version {versionId} ของ document {documentId}");
 
+        var isPdf = string.Equals(format, "pdf", StringComparison.OrdinalIgnoreCase);
+        var objectKey = isPdf ? row.PdfObjectKey : row.ObjectKey;
+        if (objectKey is null)
+            return NotFound("version นี้ไม่มีสำเนา PDF");
+        var baseName = row.FileName.EndsWith(".docx", StringComparison.OrdinalIgnoreCase)
+            ? row.FileName[..^5] : row.FileName;
+        var fileName = $"{baseName}_v{row.VersionNumber}.{(isPdf ? "pdf" : "docx")}";
+        var disposition = $"{(isPdf ? "inline" : "attachment")}; filename*=UTF-8''{Uri.EscapeDataString(fileName)}";
         var expirySeconds = Math.Clamp(minioOptions.Value.PresignedExpirySeconds, 30, 600);
-        var url = storage.GetPresignedGetUrl(minioOptions.Value.VersionsBucket, objectKey, TimeSpan.FromSeconds(expirySeconds));
+        var url = storage.GetPresignedGetUrl(minioOptions.Value.VersionsBucket, objectKey, TimeSpan.FromSeconds(expirySeconds), disposition);
 
         logger.LogInformation(
             "Version download link issued documentId={DocumentId} versionId={VersionId} userId={UserId} expirySeconds={ExpirySeconds}",

backend/WordVersioning.Api/Data/AppDbContext.cs

@@ -39,6 +39,7 @@ public class AppDbContext(DbContextOptions<AppDbContext> options) : DbContext(op
             entity.HasIndex(x => new { x.DocumentId, x.VersionNumber }).IsUnique();
 
             entity.Property(x => x.ObjectKey).HasMaxLength(1024);
+            entity.Property(x => x.PdfObjectKey).HasMaxLength(1024);
             entity.Property(x => x.ContentHash).HasMaxLength(64);
             entity.Property(x => x.Message).HasMaxLength(2048); // FR-13 commit message — นโยบายเดียวกับ Template.Description
 

backend/WordVersioning.Api/Migrations/20260908053250_AddVersionPdf.Designer.cs

@@ -0,0 +1,264 @@
+// <auto-generated />
+using System;
+using Microsoft.EntityFrameworkCore;
+using Microsoft.EntityFrameworkCore.Infrastructure;
+using Microsoft.EntityFrameworkCore.Migrations;
+using Microsoft.EntityFrameworkCore.Storage.ValueConversion;
+using Npgsql.EntityFrameworkCore.PostgreSQL.Metadata;
+using WordVersioning.Api.Data;
+
+#nullable disable
+
+namespace WordVersioning.Api.Migrations
+{
+    [DbContext(typeof(AppDbContext))]
+    [Migration("20260908053250_AddVersionPdf")]
+    partial class AddVersionPdf
+    {
+        /// <inheritdoc />
+        protected override void BuildTargetModel(ModelBuilder modelBuilder)
+        {
+#pragma warning disable 612, 618
+            modelBuilder
+                .HasAnnotation("ProductVersion", "8.0.11")
+                .HasAnnotation("Relational:MaxIdentifierLength", 63);
+
+            NpgsqlModelBuilderExtensions.UseIdentityByDefaultColumns(modelBuilder);
+
+            modelBuilder.Entity("WordVersioning.Api.Models.Document", b =>
+                {
+                    b.Property<Guid>("Id")
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("uuid");
+
+                    b.Property<string>("AddInSignature")
+                        .IsRequired()
+                        .HasMaxLength(64)
+                        .HasColumnType("character varying(64)");
+
+                    b.Property<DateTimeOffset>("CreatedAt")
+                        .HasColumnType("timestamp with time zone");
+
+                    b.Property<string>("FileName")
+                        .IsRequired()
+                        .HasMaxLength(512)
+                        .HasColumnType("character varying(512)");
+
+                    b.Property<Guid?>("TemplateId")
+                        .HasColumnType("uuid");
+
+                    b.HasKey("Id");
+
+                    b.HasIndex("TemplateId");
+
+                    b.ToTable("Documents");
+                });
+
+            modelBuilder.Entity("WordVersioning.Api.Models.DocumentFieldValue", b =>
+                {
+                    b.Property<Guid>("DocumentId")
+                        .HasColumnType("uuid");
+
+                    b.Property<string>("FieldKey")
+                        .HasMaxLength(256)
+                        .HasColumnType("character varying(256)");
+
+                    b.Property<Guid>("SourceVersionId")
+                        .HasColumnType("uuid");
+
+                    b.Property<DateTimeOffset>("UpdatedAt")
+                        .HasColumnType("timestamp with time zone");
+
+                    b.Property<string>("UpdatedByUserId")
+                        .IsRequired()
+                        .HasColumnType("text");
+
+                    b.Property<string>("Value")
+                        .IsRequired()
+                        .HasColumnType("text");
+
+                    b.HasKey("DocumentId", "FieldKey");
+
+                    b.ToTable("DocumentFieldValues");
+                });
+
+            modelBuilder.Entity("WordVersioning.Api.Models.DocumentVersion", b =>
+                {
+                    b.Property<Guid>("Id")
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("uuid");
+
+                    b.Property<string>("ContentHash")
+                        .IsRequired()
+                        .HasMaxLength(64)
+                        .HasColumnType("character varying(64)");
+
+                    b.Property<DateTimeOffset>("CreatedAt")
+                        .HasColumnType("timestamp with time zone");
+
+                    b.Property<string>("CreatedByUserId")
+                        .IsRequired()
+                        .HasColumnType("text");
+
+                    b.Property<Guid>("DocumentId")
+                        .HasColumnType("uuid");
+
+                    b.Property<string>("FieldsSnapshotJson")
+                        .HasColumnType("text");
+
+                    b.Property<string>("Message")
+                        .HasMaxLength(2048)
+                        .HasColumnType("character varying(2048)");
+
+                    b.Property<string>("ObjectKey")
+                        .IsRequired()
+                        .HasMaxLength(1024)
+                        .HasColumnType("character varying(1024)");
+
+                    b.Property<string>("PdfObjectKey")
+                        .HasMaxLength(1024)
+                        .HasColumnType("character varying(1024)");
+
+                    b.Property<int>("VersionNumber")
+                        .HasColumnType("integer");
+
+                    b.HasKey("Id");
+
+                    b.HasIndex("DocumentId", "VersionNumber")
+                        .IsUnique();
+
+                    b.ToTable("DocumentVersions");
+                });
+
+            modelBuilder.Entity("WordVersioning.Api.Models.Template", b =>
+                {
+                    b.Property<Guid>("Id")
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("uuid");
+
+                    b.Property<DateTimeOffset>("CreatedAt")
+                        .HasColumnType("timestamp with time zone");
+
+                    b.Property<string>("Description")
+                        .HasMaxLength(2048)
+                        .HasColumnType("character varying(2048)");
+
+                    b.Property<bool>("IsActive")
+                        .HasColumnType("boolean");
+
+                    b.Property<string>("Name")
+                        .IsRequired()
+                        .HasMaxLength(256)
+                        .HasColumnType("character varying(256)");
+
+                    b.Property<string>("ObjectKey")
+                        .IsRequired()
+                        .HasMaxLength(1024)
+                        .HasColumnType("character varying(1024)");
+
+                    b.Property<DateTimeOffset>("UpdatedAt")
+                        .HasColumnType("timestamp with time zone");
+
+                    b.HasKey("Id");
+
+                    b.ToTable("Templates");
+                });
+
+            modelBuilder.Entity("WordVersioning.Api.Models.TemplateField", b =>
+                {
+                    b.Property<Guid>("Id")
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("uuid");
+
+                    b.Property<string>("Editor")
+                        .HasMaxLength(16)
+                        .HasColumnType("character varying(16)");
+
+                    b.Property<bool>("IsRequired")
+                        .HasColumnType("boolean");
+
+                    b.Property<string>("Key")
+                        .IsRequired()
+                        .HasMaxLength(256)
+                        .HasColumnType("character varying(256)");
+
+                    b.Property<string>("Label")
+                        .IsRequired()
+                        .HasMaxLength(512)
+                        .HasColumnType("character varying(512)");
+
+                    b.Property<int>("SortOrder")
+                        .HasColumnType("integer");
+
+                    b.Property<Guid>("TemplateId")
+                        .HasColumnType("uuid");
+
+                    b.Property<string>("Type")
+                        .IsRequired()
+                        .HasMaxLength(16)
+                        .HasColumnType("character varying(16)");
+
+                    b.HasKey("Id");
+
+                    b.HasIndex("TemplateId", "Key")
+                        .IsUnique();
+
+                    b.ToTable("TemplateFields");
+                });
+
+            modelBuilder.Entity("WordVersioning.Api.Models.Document", b =>
+                {
+                    b.HasOne("WordVersioning.Api.Models.Template", "Template")
+                        .WithMany("Documents")
+                        .HasForeignKey("TemplateId")
+                        .OnDelete(DeleteBehavior.Restrict);
+
+                    b.Navigation("Template");
+                });
+
+            modelBuilder.Entity("WordVersioning.Api.Models.DocumentFieldValue", b =>
+                {
+                    b.HasOne("WordVersioning.Api.Models.Document", null)
+                        .WithMany()
+                        .HasForeignKey("DocumentId")
+                        .OnDelete(DeleteBehavior.Cascade)
+                        .IsRequired();
+                });
+
+            modelBuilder.Entity("WordVersioning.Api.Models.DocumentVersion", b =>
+                {
+                    b.HasOne("WordVersioning.Api.Models.Document", "Document")
+                        .WithMany("Versions")
+                        .HasForeignKey("DocumentId")
+                        .OnDelete(DeleteBehavior.Cascade)
+                        .IsRequired();
+
+                    b.Navigation("Document");
+                });
+
+            modelBuilder.Entity("WordVersioning.Api.Models.TemplateField", b =>
+                {
+                    b.HasOne("WordVersioning.Api.Models.Template", "Template")
+                        .WithMany("Fields")
+                        .HasForeignKey("TemplateId")
+                        .OnDelete(DeleteBehavior.Cascade)
+                        .IsRequired();
+
+                    b.Navigation("Template");
+                });
+
+            modelBuilder.Entity("WordVersioning.Api.Models.Document", b =>
+                {
+                    b.Navigation("Versions");
+                });
+
+            modelBuilder.Entity("WordVersioning.Api.Models.Template", b =>
+                {
+                    b.Navigation("Documents");
+
+                    b.Navigation("Fields");
+                });
+#pragma warning restore 612, 618
+        }
+    }
+}

backend/WordVersioning.Api/Migrations/20260908053250_AddVersionPdf.cs

@@ -0,0 +1,29 @@
+using Microsoft.EntityFrameworkCore.Migrations;
+
+#nullable disable
+
+namespace WordVersioning.Api.Migrations
+{
+    /// <inheritdoc />
+    public partial class AddVersionPdf : Migration
+    {
+        /// <inheritdoc />
+        protected override void Up(MigrationBuilder migrationBuilder)
+        {
+            migrationBuilder.AddColumn<string>(
+                name: "PdfObjectKey",
+                table: "DocumentVersions",
+                type: "character varying(1024)",
+                maxLength: 1024,
+                nullable: true);
+        }
+
+        /// <inheritdoc />
+        protected override void Down(MigrationBuilder migrationBuilder)
+        {
+            migrationBuilder.DropColumn(
+                name: "PdfObjectKey",
+                table: "DocumentVersions");
+        }
+    }
+}

backend/WordVersioning.Api/Migrations/AppDbContextModelSnapshot.cs

@@ -112,6 +112,10 @@ namespace WordVersioning.Api.Migrations
                         .HasMaxLength(1024)
                         .HasColumnType("character varying(1024)");
 
+                    b.Property<string>("PdfObjectKey")
+                        .HasMaxLength(1024)
+                        .HasColumnType("character varying(1024)");
+
                     b.Property<int>("VersionNumber")
                         .HasColumnType("integer");
 

backend/WordVersioning.Api/Models/DocumentVersion.cs

@@ -9,12 +9,15 @@ public class DocumentVersion
 
     public Document? Document { get; set; }
 
-    /// <summary>เริ่มที่ 1 — auto increment ต่อ document (unique index กัน race)</summary>
+    /// <summary>generate เริ่ม 0; add-in เริ่ม 1 — auto increment ต่อ document (unique index กัน race)</summary>
     public int VersionNumber { get; set; }
 
     /// <summary>MinIO object key: {documentId}/v{VersionNumber:D4}_{clientVersionId}.docx</summary>
     public string ObjectKey { get; set; } = string.Empty;
 
+    /// <summary>FR-15: null เมื่อไม่มี PDF (v0 หรือ capture/upload ล้ม)</summary>
+    public string? PdfObjectKey { get; set; }
+
     /// <summary>SHA256 hex ของไฟล์ (ตรวจ integrity ภายหลัง)</summary>
     public string ContentHash { get; set; } = string.Empty;
 

backend/WordVersioning.Api/Models/VersionDtos.cs

@@ -9,6 +9,8 @@ public class UploadVersionRequest
     [Required]
     public IFormFile File { get; set; } = null!;
 
+    public IFormFile? Pdf { get; set; }
+
     /// <summary>GUID ที่ client generate ต่อ version — ใช้เป็นส่วนหนึ่งของ object key</summary>
     [Required]
     public string ClientVersionId { get; set; } = string.Empty;
@@ -20,7 +22,7 @@ public class UploadVersionRequest
     public string? Message { get; set; }
 }
 
-public record UploadVersionResponse(Guid VersionId, int VersionNumber);
+public record UploadVersionResponse(Guid VersionId, int VersionNumber, bool HasPdf);
 
 /// <summary>body ของ POST /api/documents/generate (FR-10)</summary>
 public class GenerateDocumentRequest
@@ -45,7 +47,8 @@ public record VersionListItem(
     string CreatedByUserId,
     string ContentHash,
     object? Fields,
-    string? Message);
+    string? Message,
+    bool HasPdf);
 
 /// <summary>response ของ GET .../download-link — presigned URL อายุสั้นให้เปิดในเบราว์เซอร์ของผู้ใช้</summary>
 public record VersionDownloadLinkResponse(string Url, DateTimeOffset ExpiresAt);

backend/WordVersioning.Api/Services/ObjectStorageService.cs

@@ -15,7 +15,7 @@ public interface IObjectStorageService
 
     /// <summary>สร้าง presigned GET URL อายุสั้น — ให้เปิดในเบราว์เซอร์ของผู้ใช้โดยตรง
     /// (webview ของ Word ทิ้ง blob download แบบเงียบๆ — spec อนุญาต presigned URL อายุสั้นสำหรับดาวน์โหลด)</summary>
-    string GetPresignedGetUrl(string bucket, string key, TimeSpan expiry);
+    string GetPresignedGetUrl(string bucket, string key, TimeSpan expiry, string? contentDisposition = null);
 }
 
 /// <summary>Wrapper เรียก MinIO ผ่าน AWSSDK.S3 (S3-compatible API)</summary>
@@ -76,7 +76,7 @@ public class ObjectStorageService : IObjectStorageService
         return new S3ResponseStream(response);
     }
 
-    public string GetPresignedGetUrl(string bucket, string key, TimeSpan expiry)
+    public string GetPresignedGetUrl(string bucket, string key, TimeSpan expiry, string? contentDisposition = null)
     {
         var request = new GetPreSignedUrlRequest
         {
@@ -85,6 +85,8 @@ public class ObjectStorageService : IObjectStorageService
             Verb = HttpVerb.GET,
             Expires = DateTime.UtcNow + expiry,
         };
+        if (contentDisposition is not null)
+            request.ResponseHeaderOverrides.ContentDisposition = contentDisposition;
         // GetPreSignedURL เป็น sync (เซ็น SigV4 ฝั่ง client ไม่ยิง network)
         var url = _s3.GetPreSignedURL(request);
         // AWSSDK v4 บังคับ https ใน presigned URL เสมอ (ไม่สน UseHttp) — สลับ scheme เองตาม config ได้

backend/WordVersioning.Api/Services/PdfUploadValidation.cs

@@ -0,0 +1,12 @@
+namespace WordVersioning.Api.Services;
+
+public static class PdfUploadValidation
+{
+    public const string PdfContentType = "application/pdf";
+
+    public static bool IsValidPdf(IFormFile file) =>
+        file.FileName.EndsWith(".pdf", StringComparison.OrdinalIgnoreCase)
+        && (string.IsNullOrWhiteSpace(file.ContentType)
+            || file.ContentType.Equals(PdfContentType, StringComparison.OrdinalIgnoreCase)
+            || file.ContentType.Equals("application/octet-stream", StringComparison.OrdinalIgnoreCase));
+}