test(gh-aw): enforce shell input security contract over compiled output (#1834)

.github/workflows/squad-ci.yml

@@ -167,10 +167,12 @@ jobs:
         env:
           GH_TOKEN: ${{ github.token }}
       - name: Install gh-aw extension
-        # Required so `gh aw --version` succeeds and the compile-gate test in
-        # test/gh-aw-quality.test.ts is NOT skipped. Without this step the test
-        # uses `it.skipIf(!ghAwAvailable)` and always skips — which is
-        # indistinguishable from having no gate at all. See #1732.
+        # Required so `gh aw --version` succeeds and the compiled-workflow gates in
+        # test/gh-aw-quality.test.ts can compile squad.md. Those gates FAIL CLOSED:
+        # if gh aw is absent they hard-fail with this exact install command, rather
+        # than skipping — a skipped gate is indistinguishable from no gate. This
+        # includes the shell input security contract gate (#1834) and the compile
+        # contract (#1732).
         run: gh extension install github/gh-aw
         env:
           GH_TOKEN: ${{ github.token }}

test/fixtures/gh-aw-shell-contract/violating.lock.yml

@@ -0,0 +1,42 @@
+# Positive-control fixture for the gh-aw shell input security contract gate (#1834).
+#
+# This is a compiled-shaped GitHub Actions lock fragment whose `run:` blocks each
+# violate one anti-pattern from workflows/squad.md §"Shell input security contract".
+# It exists so the gate is PROVEN capable of failing, not assumed to be: the gate's
+# own test feeds this file through the same extractRunBlocks()/scanRunBlocks() used
+# on the real squad.lock.yml and asserts each token is named with its file and line.
+#
+# RETRO's acceptance bar (issue #1834): "A gate that cannot turn red on a fixture
+# containing `run: printf '%s\n' \"${{ github.event.issue.body }}\"` is not a valid
+# gate." That exact line is the first block below.
+#
+# DO NOT install or reference this file as a workflow. It lives under test/fixtures/
+# so actionlint and gh-aw never see it; only the gate's unit test reads it.
+name: shell-contract-positive-control
+on:
+  issues:
+    types: [opened]
+jobs:
+  violations:
+    runs-on: ubuntu-latest
+    steps:
+      - name: UNTRUSTED_TEMPLATE_IN_RUN — raw event expression inside run
+        run: printf '%s\n' "${{ github.event.issue.body }}"
+      - name: UNTRUSTED_PRINTF_FORMAT — body in printf's format slot
+        env:
+          SQUAD_TRIGGER_BODY: ${{ github.event.issue.body }}
+        run: |
+          body="${SQUAD_TRIGGER_BODY-}"
+          printf "$body"
+      - name: UNTRUSTED_COMMAND_STRING — body built into a command string
+        env:
+          SQUAD_TRIGGER_BODY: ${{ github.event.issue.body }}
+        run: |
+          eval "$SQUAD_TRIGGER_BODY"
+          bash -c "handle $SQUAD_TRIGGER_BODY"
+      - name: UNTRUSTED_AWK_PROGRAM_OR_VAR — body through awk -v and awk program
+        env:
+          SQUAD_TRIGGER_BODY: ${{ github.event.issue.body }}
+        run: |
+          awk -v body="$SQUAD_TRIGGER_BODY" 'BEGIN { print body }'
+          awk "/$SQUAD_TRIGGER_BODY/ { print }"