ci: add CodeQL, Scorecard, and dependency-review workflows

- codeql.yml: reuses existing .github/codeql/codeql-config.yml
  (security-extended + security-and-quality queries), weekly + per-PR.
- scorecard.yml: weekly OpenSSF Scorecard analysis, publishes to
  scorecard.dev and uploads SARIF to the Security tab.
- dependency-review.yml: blocks PRs that introduce vulnerable
  dependencies at moderate severity or above.

All actions SHA-pinned. Covers: ER-19/20/21, GH-19.

Signed-off-by: Sebastian Mendel <info@sebastianmendel.de>

Author: CybotTM

.github/workflows/codeql.yml

@@ -0,0 +1,42 @@
+name: CodeQL
+
+on:
+  push:
+    branches: [main]
+  pull_request:
+    branches: [main]
+  schedule:
+    # Weekly, Monday 06:00 UTC — catches advisories for deps that change slowly.
+    - cron: '0 6 * * 1'
+  workflow_dispatch:
+
+permissions:
+  contents: read
+
+jobs:
+  analyze:
+    name: Analyze (${{ matrix.language }})
+    runs-on: ubuntu-latest
+    permissions:
+      actions: read
+      contents: read
+      security-events: write
+    strategy:
+      fail-fast: false
+      matrix:
+        language: [python]
+    steps:
+      - name: Checkout
+        uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6.0.2
+
+      - name: Initialize CodeQL
+        uses: github/codeql-action/init@95e58e9a2cdfd71adc6e0353d5c52f41a045d225 # v4.35.2
+        with:
+          languages: ${{ matrix.language }}
+          config-file: ./.github/codeql/codeql-config.yml
+          queries: security-extended,security-and-quality
+
+      - name: Perform CodeQL Analysis
+        uses: github/codeql-action/analyze@95e58e9a2cdfd71adc6e0353d5c52f41a045d225 # v4.35.2
+        with:
+          category: /language:${{ matrix.language }}

.github/workflows/dependency-review.yml

@@ -0,0 +1,22 @@
+name: Dependency Review
+
+on:
+  pull_request:
+    branches: [main]
+
+permissions:
+  contents: read
+
+jobs:
+  dependency-review:
+    name: Review dependency changes
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout
+        uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6.0.2
+
+      - name: Dependency Review
+        uses: actions/dependency-review-action@2031cfc080254a8a887f58cffee85186f0e49e48 # v4.9.0
+        with:
+          fail-on-severity: moderate
+          comment-summary-in-pr: true

.github/workflows/scorecard.yml

@@ -0,0 +1,38 @@
+name: OpenSSF Scorecard
+
+on:
+  branch_protection_rule:
+  schedule:
+    - cron: '0 6 * * 1'
+  push:
+    branches: [main]
+  workflow_dispatch:
+
+permissions: read-all
+
+jobs:
+  analysis:
+    name: Scorecard analysis
+    runs-on: ubuntu-latest
+    permissions:
+      security-events: write
+      id-token: write
+      contents: read
+      actions: read
+    steps:
+      - name: Checkout
+        uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6.0.2
+        with:
+          persist-credentials: false
+
+      - name: Run analysis
+        uses: ossf/scorecard-action@4eaacf0543bb3f2c246792bd56e8cdeffafb205a # v2.4.3
+        with:
+          results_file: results.sarif
+          results_format: sarif
+          publish_results: true
+
+      - name: Upload SARIF
+        uses: github/codeql-action/upload-sarif@95e58e9a2cdfd71adc6e0353d5c52f41a045d225 # v4.35.2
+        with:
+          sarif_file: results.sarif