Add broken link check: general and pr

Signed-off-by: peppi-lotta <[email protected]>

.github/workflows/broken-link-check.yml

@@ -0,0 +1,37 @@
+name: Check Links
+on:
+  workflow_call
+
+permissions: {}
+
+jobs:
+  check:
+    runs-on: ubuntu-latest
+
+    permissions:
+      contents: read
+      issues: write
+
+    steps:
+    - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
+
+    - name: Link Checker
+      id: linkcheck
+      uses: lycheeverse/lychee-action@f796c8b7d468feb9b8c0a46da3fac0af6874d374 # v2.2.0
+      with:
+        args: |
+          --user-agent "Mozilla/5.0 (Windows NT 6.1; Win64; x64; rv:135.0) Gecko/20100101 Firefox/135.0" 
+          --root-dir "$(pwd)/" 
+          --fallback-extensions "md" 
+          "./**/*.md"
+        output: /tmp/lychee_output.md
+        fail: false
+
+    - name: Create Issue From File
+      if: steps.linkcheck.outputs.exit_code != 0
+      uses: peter-evans/create-issue-from-file@e8ef132d6df98ed982188e460ebb3b5d4ef3a9cd # v5.0.1
+      with:
+        title: Link Checker Report
+        content-filepath: /tmp/lychee_output.md
+        labels: |
+          kind/bug

.github/workflows/pr-link-check.yml

@@ -0,0 +1,56 @@
+name: Check Links In Pull Requests
+permissions: {}
+
+on:
+  workflow_call:
+
+concurrency:
+  group: ${{ github.workflow }}-${{ github.ref }}
+  cancel-in-progress: true
+
+jobs:
+  check-links:
+    runs-on: ubuntu-latest
+
+    steps:
+      - name: Clone repository
+        uses: actions/checkout@v4
+        with:
+          fetch-depth: 0
+          ref: ${{github.event.pull_request.head.ref}}
+          repository: ${{github.event.pull_request.head.repo.full_name}}
+
+      - name: Checkout base branch
+        run: git checkout ${{ github.event.pull_request.base.ref }}
+
+      - name: Get list of changed Markdown files
+        id: changed-files
+        run: |
+          git diff --name-only origin/${{ github.event.pull_request.base.ref }}...${{ github.head_ref }} -- '*.md' > changed-files.txt
+          cat changed-files.txt
+
+      - name: Switch to PR branch
+        run: git checkout ${{ github.head_ref }}
+
+      - name: Check links in changed files
+        uses: lycheeverse/lychee-action@v2
+        with:
+          failIfEmpty: false
+          args: |
+            --no-progress
+            $(cat changed-files.txt | tr '\n' ' ')
+
+      - name: Provide helpful failure message
+        if: failure()
+        run: |
+          echo "::error::Link check failed! Please review the broken links reported above."
+          echo ""
+          echo "If certain links are valid but fail due to:"
+          echo "- CAPTCHA challenges"
+          echo "- IP blocking"
+          echo "- Authentication requirements"
+          echo "- Rate limiting"
+          echo ""
+          echo "Consider adding them to .lycheeignore to bypass future checks."
+          echo "Format: Add one URL pattern per line"
+          exit 1