[autofix.ci] apply automated fixes

Bumps [docker/login-action](https://github.com/docker/login-action) from 3 to 4.
- [Release notes](https://github.com/docker/login-action/releases)
- [Commits](https://github.com/docker/login-action/compare/v3...v4)

---
updated-dependencies:
- dependency-name: docker/login-action
  dependency-version: '4'
  dependency-type: direct:production
  update-type: version-update:semver-major
...

Signed-off-by: dependabot[bot] <support@github.com>

.github/workflows/ci.yml

@@ -375,13 +375,13 @@ jobs:
         uses: actions/checkout@v6
 
       - name: Login to Docker Hub
-        uses: docker/login-action@v3
+        uses: docker/login-action@v4
         with:
           username: ${{ vars.DOCKERHUB_USERNAME }}
           password: ${{ secrets.DOCKERHUB_TOKEN }}
 
       - name: Log in to GitHub Container Registry
-        uses: docker/login-action@v3
+        uses: docker/login-action@v4
         with:
           registry: ${{ env.REGISTRY }}
           username: ${{ github.actor }}

.github/workflows/release.yml

@@ -91,13 +91,13 @@ jobs:
         uses: actions/checkout@v6
 
       - name: Login to Docker Hub
-        uses: docker/login-action@v3
+        uses: docker/login-action@v4
         with:
           username: ${{ vars.DOCKERHUB_USERNAME }}
           password: ${{ secrets.DOCKERHUB_TOKEN }}
 
       - name: Log in to GitHub Container Registry
-        uses: docker/login-action@v3
+        uses: docker/login-action@v4
         with:
           registry: ${{ env.REGISTRY }}
           username: ${{ github.actor }}

go.mod

@@ -6,8 +6,8 @@ toolchain go1.25.5
 
 require (
 	github.com/fumiama/go-docx v0.0.0-20250506085032-0c30fd09304b
-	golang.org/x/net v0.48.0
-	golang.org/x/text v0.32.0
+	golang.org/x/net v0.49.0
+	golang.org/x/text v0.33.0
 )
 
 require (

go.sum

@@ -4,7 +4,7 @@ github.com/fumiama/imgsz v0.0.4 h1:Lsasu2hdSSFS+vnD+nvR1UkiRMK7hcpyYCC0FzgSMFI=
 github.com/fumiama/imgsz v0.0.4/go.mod h1:bISOQVTlw9sRytPwe8ir7tAaEmyz9hSNj9n8mXMBG0E=
 golang.org/x/image v0.34.0 h1:33gCkyw9hmwbZJeZkct8XyR11yH889EQt/QH4VmXMn8=
 golang.org/x/image v0.34.0/go.mod h1:2RNFBZRB+vnwwFil8GkMdRvrJOFd1AzdZI6vOY+eJVU=
-golang.org/x/net v0.48.0 h1:zyQRTTrjc33Lhh0fBgT/H3oZq9WuvRR5gPC70xpDiQU=
-golang.org/x/net v0.48.0/go.mod h1:+ndRgGjkh8FGtu1w1FGbEC31if4VrNVMuKTgcAAnQRY=
-golang.org/x/text v0.32.0 h1:ZD01bjUt1FQ9WJ0ClOL5vxgxOI/sVCNgX1YtKwcY0mU=
-golang.org/x/text v0.32.0/go.mod h1:o/rUWzghvpD5TXrTIBuJU77MTaN0ljMWE47kxGJQ7jY=
+golang.org/x/net v0.49.0 h1:eeHFmOGUTtaaPSGNmjBKpbng9MulQsJURQUAfUwY++o=
+golang.org/x/net v0.49.0/go.mod h1:/ysNB2EvaqvesRkuLAyjI1ycPZlQHM3q01F02UY/MV8=
+golang.org/x/text v0.33.0 h1:B3njUFyqtHDUI5jMn1YIr5B0IE2U0qck04r6d4KPAxE=
+golang.org/x/text v0.33.0/go.mod h1:LuMebE6+rBincTi9+xWTY8TztLzKHc/9C1uBCG27+q8=

internal/exporters/markdown.go

@@ -40,19 +40,19 @@ func (e *MarkdownExporter) Export(course *models.Course, outputPath string) erro
 	var buf bytes.Buffer
 
 	// Write course header
-	buf.WriteString(fmt.Sprintf("# %s\n\n", course.Course.Title))
+	fmt.Fprintf(&buf, "# %s\n\n", course.Course.Title)
 
 	if course.Course.Description != "" {
-		buf.WriteString(fmt.Sprintf("%s\n\n", e.htmlCleaner.CleanHTML(course.Course.Description)))
+		fmt.Fprintf(&buf, "%s\n\n", e.htmlCleaner.CleanHTML(course.Course.Description))
 	}
 
 	// Add metadata
 	buf.WriteString("## Course Information\n\n")
-	buf.WriteString(fmt.Sprintf("- **Course ID**: %s\n", course.Course.ID))
-	buf.WriteString(fmt.Sprintf("- **Share ID**: %s\n", course.ShareID))
-	buf.WriteString(fmt.Sprintf("- **Navigation Mode**: %s\n", course.Course.NavigationMode))
+	fmt.Fprintf(&buf, "- **Course ID**: %s\n", course.Course.ID)
+	fmt.Fprintf(&buf, "- **Share ID**: %s\n", course.ShareID)
+	fmt.Fprintf(&buf, "- **Navigation Mode**: %s\n", course.Course.NavigationMode)
 	if course.Course.ExportSettings != nil {
-		buf.WriteString(fmt.Sprintf("- **Export Format**: %s\n", course.Course.ExportSettings.Format))
+		fmt.Fprintf(&buf, "- **Export Format**: %s\n", course.Course.ExportSettings.Format)
 	}
 	buf.WriteString("\n---\n\n")
 
@@ -60,15 +60,15 @@ func (e *MarkdownExporter) Export(course *models.Course, outputPath string) erro
 	lessonCounter := 0
 	for _, lesson := range course.Course.Lessons {
 		if lesson.Type == "section" {
-			buf.WriteString(fmt.Sprintf("# %s\n\n", lesson.Title))
+			fmt.Fprintf(&buf, "# %s\n\n", lesson.Title)
 			continue
 		}
 
 		lessonCounter++
-		buf.WriteString(fmt.Sprintf("## Lesson %d: %s\n\n", lessonCounter, lesson.Title))
+		fmt.Fprintf(&buf, "## Lesson %d: %s\n\n", lessonCounter, lesson.Title)
 
 		if lesson.Description != "" {
-			buf.WriteString(fmt.Sprintf("%s\n\n", e.htmlCleaner.CleanHTML(lesson.Description)))
+			fmt.Fprintf(&buf, "%s\n\n", e.htmlCleaner.CleanHTML(lesson.Description))
 		}
 
 		// Process lesson items