ci: add Forgejo verification workflow

.forgejo/workflows/verify.yml

@@ -0,0 +1,31 @@
+name: Verify
+
+on:
+  pull_request:
+  push:
+
+permissions:
+  contents: read
+
+jobs:
+  source-contract:
+    runs-on: ubuntu-latest
+    timeout-minutes: 15
+    steps:
+      - uses: actions/checkout@v4
+
+      - name: Verify repository entrypoints
+        run: |
+          test -f app/build.sh
+          test -f app/src/ac/ac_svr.pgc
+          test -d app/src/ac/svc
+          test -f docker/docker-compose.yml
+
+      - name: Validate JSON artifacts
+        run: git ls-files -z '*.json' | xargs -0 -r -n1 python3 -m json.tool >/dev/null
+
+      - name: Validate shell scripts
+        run: git ls-files -z '*.sh' | xargs -0 -r -n1 bash -n
+
+      - name: Compile analysis tools
+        run: python3 -m compileall -q tools