ci: add security scanning workflow (pip-audit + trivy)

.github/workflows/security.yml

@@ -0,0 +1,52 @@
+name: Security Scan
+
+on:
+  push:
+    branches: [main]
+  pull_request:
+    branches: [main]
+  schedule:
+    - cron: "0 6 * * 1"  # щопонеділка о 6:00 UTC
+
+permissions:
+  contents: read
+  security-events: write  # для завантаження SARIF у GitHub Security tab
+
+jobs:
+  pip-audit:
+    name: pip-audit (Python deps)
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+
+      - uses: actions/setup-python@v5
+        with:
+          python-version: "3.12"
+
+      - name: Install pip-audit
+        run: pip install pip-audit
+
+      - name: Audit Python dependencies
+        run: pip-audit -r api/requirements.txt --strict
+
+  trivy:
+    name: trivy (vuln, second opinion)
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+
+      - name: Run Trivy
+        uses: aquasecurity/trivy-action@0.30.0
+        with:
+          scan-type: fs
+          scan-ref: .
+          scanners: vuln
+          severity: HIGH,CRITICAL
+          format: sarif
+          output: trivy-results.sarif
+
+      - name: Upload Trivy results to GitHub Security
+        uses: github/codeql-action/upload-sarif@v3
+        if: always()
+        with:
+          sarif_file: trivy-results.sarif