ci: add GHA and license linters

Author: MegaRedHand

.github/workflows/pr_lint_gha.yaml

@@ -0,0 +1,29 @@
+name: GitHub Actions
+
+on:
+  workflow_dispatch:
+  pull_request:
+    branches: ["**"]
+    paths:
+      - ".github/**.yaml"
+      - ".github/**.yml"
+
+permissions:
+  contents: read
+
+concurrency:
+  group: ${{ github.workflow }}-${{ github.head_ref || github.run_id }}
+  cancel-in-progress: true
+
+jobs:
+  lint:
+    name: Lint
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v6
+
+      - name: Install actionlint
+        run: bash <(curl -s https://raw.githubusercontent.com/rhysd/actionlint/main/scripts/download-actionlint.bash)
+
+      - name: Run actionlint
+        run: ./actionlint

.github/workflows/pr_lint_license.yaml

@@ -0,0 +1,47 @@
+name: Check License
+
+on:
+  workflow_dispatch:
+  pull_request:
+    branches: ["**"]
+    paths:
+      - "**/Cargo.toml"
+      - "LICENSE*"
+      - ".github/workflows/pr_lint_license.yaml"
+
+permissions:
+  contents: read
+
+concurrency:
+  group: ${{ github.workflow }}-${{ github.head_ref || github.run_id }}
+  cancel-in-progress: true
+
+jobs:
+  check-license:
+    name: Verify License
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v6
+
+      - name: Check LICENSE file exists
+        run: |
+          if [ ! -f LICENSE ]; then
+            echo "::error::LICENSE file is missing"
+            exit 1
+          fi
+          echo "License file present"
+
+      - name: Check all packages reference LICENSE
+        run: |
+          MISSING=$(cargo metadata --format-version 1 --no-deps 2>/dev/null | \
+            jq -r '.packages[] | select(.license != "LICENSE") | .name')
+
+          if [ -n "$MISSING" ]; then
+            echo "::error::The following packages do not reference 'LICENSE':"
+            echo "$MISSING"
+            echo ""
+            echo "Ensure each Cargo.toml has: license = \"LICENSE\""
+            exit 1
+          fi
+
+          echo "All packages correctly reference LICENSE file"