ci: add CodeQL advanced setup to scan pull requests before merge

Author: nopoz

.github/workflows/codeql.yml

@@ -0,0 +1,39 @@
+name: CodeQL
+
+# Advanced setup so CodeQL also runs on pull requests (including from forks),
+# surfacing findings before merge instead of only after a change lands on dev.
+on:
+  push:
+    branches: [dev, main]
+  pull_request:
+    branches: [dev]
+
+permissions:
+  contents: read
+
+jobs:
+  analyze:
+    name: Analyze (${{ matrix.language }})
+    runs-on: ubuntu-latest
+    permissions:
+      security-events: write
+      actions: read
+      contents: read
+    strategy:
+      fail-fast: false
+      matrix:
+        language: [actions, javascript-typescript, python]
+    steps:
+      - name: Checkout
+        uses: actions/checkout@9c091bb21b7c1c1d1991bb908d89e4e9dddfe3e0  # v7.0.0
+        with:
+          persist-credentials: false
+      - name: Initialize CodeQL
+        uses: github/codeql-action/init@8aad20d150bbac5944a9f9d289da16a4b0d87c1e  # v4.36.2
+        with:
+          languages: ${{ matrix.language }}
+          build-mode: none
+      - name: Perform CodeQL Analysis
+        uses: github/codeql-action/analyze@8aad20d150bbac5944a9f9d289da16a4b0d87c1e  # v4.36.2
+        with:
+          category: "/language:${{ matrix.language }}"