feat: implement article version content storage and reconstruction logic; enhance article repository with version management

server/internal/tenant/repository/article_repo.go

@@ -30,11 +30,12 @@ type ArticleRepository interface {
 }
 
 type articleRepository struct {
-	q generated.Querier
+	db generated.DBTX
+	q  generated.Querier
 }
 
 func NewArticleRepository(db generated.DBTX) ArticleRepository {
-	return &articleRepository{q: newQuerier(db)}
+	return &articleRepository{db: db, q: newQuerier(db)}
 }
 
 func (r *articleRepository) CreateArticle(ctx context.Context, input CreateArticleInput) (int64, error) {
@@ -46,15 +47,42 @@ func (r *articleRepository) CreateArticle(ctx context.Context, input CreateArtic
 }
 
 func (r *articleRepository) CreateArticleVersion(ctx context.Context, input CreateArticleVersionInput) (int64, error) {
-	return r.q.CreateArticleVersion(ctx, generated.CreateArticleVersionParams{
-		ArticleID:       input.ArticleID,
-		VersionNo:       int32(input.VersionNo),
-		Title:           pgText(&input.Title),
-		HtmlContent:     pgText(&input.HTMLContent),
-		MarkdownContent: pgText(&input.MarkdownContent),
-		WordCount:       int32(input.WordCount),
-		SourceLabel:     pgText(&input.SourceLabel),
+	previous, err := loadLatestArticleVersionContent(ctx, r.db, input.ArticleID)
+	if err != nil {
+		return 0, err
+	}
+
+	storedHTML, storedMarkdown := buildArticleVersionDiffStorage(*previous, ArticleVersionContent{
+		HTMLContent:     stringPtr(input.HTMLContent),
+		MarkdownContent: stringPtr(input.MarkdownContent),
 	})
+
+	var versionID int64
+	err = r.db.QueryRow(ctx, `
+		INSERT INTO article_versions (
+			article_id,
+			version_no,
+			title,
+			html_content,
+			markdown_content,
+			word_count,
+			source_label
+		)
+		VALUES ($1, $2, $3, $4, $5, $6, $7)
+		RETURNING id
+	`,
+		input.ArticleID,
+		input.VersionNo,
+		pgText(&input.Title),
+		pgText(storedHTML),
+		pgText(storedMarkdown),
+		input.WordCount,
+		pgText(&input.SourceLabel),
+	).Scan(&versionID)
+	if err != nil {
+		return 0, err
+	}
+	return versionID, nil
 }
 
 func (r *articleRepository) UpdateArticleCurrentVersion(ctx context.Context, articleID, tenantID, versionID int64) error {