add standard workflows

.github/workflows/core-ci.yml

@@ -0,0 +1,21 @@
+name: CORE CI
+
+on:
+  pull_request:
+    branches: [ main, master ]
+  push:
+    branches: [ main, master ]
+
+jobs:
+  guard:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Guardrail
+        run: echo "CORE repo guardrail active"
+
+  lint:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+      - name: Lint placeholder
+        run: echo "Add lint/test here"