ci: add Grype CVE scanning workflow

Scans all dependencies for known vulnerabilities on push, PR, and
weekly schedule. Uploads SARIF to the Security tab and a human-readable
table report as an artifact. Fails on high severity with a fix available.

Author: coopernetes

.github/workflows/cve.yml

@@ -0,0 +1,63 @@
+name: CVE Scanning
+
+permissions:
+  contents: read
+
+on:
+  push:
+    branches: ['main']
+  pull_request:
+    branches: ['main']
+  schedule:
+    - cron: '0 6 * * 1' # Weekly Monday 6am UTC
+
+jobs:
+  grype:
+    name: Grype dependency scan
+    runs-on: ubuntu-latest
+    permissions:
+      contents: read
+      security-events: write
+    steps:
+      - name: Harden Runner
+        uses: step-security/harden-runner@9af89fc71515a100421586dfdb3dc9c984fbf411 # v2.19.4
+        with:
+          egress-policy: audit
+
+      - name: Checkout
+        uses: actions/checkout@df4cb1c069e1874edd31b4311f1884172cec0e10 # v6
+
+      - name: Scan project
+        uses: anchore/scan-action@e1165082ffb1fe366ebaf02d8526e7c4989ea9d2 # v7
+        id: scan
+        with:
+          path: .
+          fail-build: true
+          severity-cutoff: high
+          only-fixed: true
+          config: .grype.yaml
+
+      - name: Upload SARIF report
+        if: ${{ always() }}
+        uses: github/codeql-action/upload-sarif@8aad20d150bbac5944a9f9d289da16a4b0d87c1e # v4
+        with:
+          sarif_file: ${{ steps.scan.outputs.sarif }}
+
+      - name: Generate table report
+        if: ${{ always() }}
+        run: |
+          export PATH="$(dirname $(find /opt/hostedtoolcache/grype -name grype -type f | head -1)):$PATH"
+          grype dir:. \
+            --config .grype.yaml \
+            --only-fixed \
+            --output table | tee grype-report.txt || true
+
+      - name: Upload scan reports
+        if: ${{ always() }}
+        uses: actions/upload-artifact@043fb46d1a93c77aae656e7c1c64a875d1fc6a0a # v7
+        with:
+          name: grype-scan
+          path: |
+            grype-report.txt
+            ${{ steps.scan.outputs.json }}
+          retention-days: 30

.grype.yaml

@@ -0,0 +1,6 @@
+fail-on-severity: high
+sort-by: severity
+
+ignore:
+  - fix-state: 'wont-fix'
+  - fix-state: 'not-fixed'