feat: shared scan baseline as a reusable workflow

.github/workflows/scan.yml

@@ -0,0 +1,79 @@
+# Shared scan baseline for uinaf repositories: secret scanning plus workflow
+# lint. Repositories call this with a thin caller workflow; version bumps and
+# digest pins change here, once.
+#
+# Every image is pinned by digest, not tag. A tag is mutable, so a version tag
+# is a promise the registry can break, and each of these containers gets the
+# whole repository, one of them with a token.
+
+name: Scan
+
+on:
+  workflow_call:
+
+permissions:
+  contents: read
+
+jobs:
+  gitleaks:
+    name: Gitleaks
+    runs-on: ubuntu-latest
+    timeout-minutes: 10
+    steps:
+      - uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1 # v7.0.1
+        with:
+          persist-credentials: false
+          fetch-depth: 0
+      - name: Scan Git history
+        run: |
+          docker run --rm --network none -v "$PWD:/repo:ro" \
+            zricethezav/gitleaks@sha256:c00b6bd0aeb3071cbcb79009cb16a60dd9e0a7c60e2be9ab65d25e6bc8abbb7f \
+            detect --source /repo --redact --no-banner --log-level error # v8.30.1
+
+  trufflehog:
+    name: TruffleHog
+    runs-on: ubuntu-latest
+    timeout-minutes: 10
+    steps:
+      - uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1 # v7.0.1
+        with:
+          persist-credentials: false
+          fetch-depth: 0
+      - name: Scan for verified secrets
+        run: |
+          docker run --rm -v "$PWD:/repo:ro" \
+            trufflesecurity/trufflehog@sha256:ff4c95e9df7d645daf2140e3ca1039031c63106268d5fbb25feb43ceca1bcc33 \
+            git file:///repo --no-update --fail --results=verified # 3.97.0
+
+  actionlint:
+    name: Actionlint
+    runs-on: ubuntu-latest
+    timeout-minutes: 5
+    steps:
+      - uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1 # v7.0.1
+        with:
+          persist-credentials: false
+      - name: Lint workflows
+        run: |
+          docker run --rm -v "$PWD:/repo" --workdir /repo \
+            rhysd/actionlint@sha256:b1934ee5f1c509618f2508e6eb47ee0d3520686341fec936f3b79331f9315667 \
+            -color # 1.7.12
+
+  zizmor:
+    name: Zizmor
+    runs-on: ubuntu-latest
+    timeout-minutes: 5
+    steps:
+      - uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1 # v7.0.1
+        with:
+          persist-credentials: false
+      # Keep this at 1.28.0 or newer. 1.27.0 is yanked for GHSA-f42p-wjw5-97qh:
+      # it logs the parsed config, the GH_TOKEN below included, once verbose
+      # output is on.
+      - name: Audit workflow security
+        env:
+          GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+        run: |
+          docker run --rm -e GH_TOKEN -v "$PWD:/repo" \
+            ghcr.io/zizmorcore/zizmor@sha256:863026d54f91271b10b60b67ad8054cb37120167e162482597db102b3026a284 \
+            /repo # 1.29.0