feat: add pre-commit hook for license header insertion (#1492)

This PR adds pre-commit hooks for license header validation and CI workflow integration.

Author: PooyaRaki

.github/workflows/test.yml

@@ -1,3 +1,4 @@
+# SPDX-License-Identifier: FSL-1.1-MIT
 name: "CI"
 
 # The workflow should be triggered on any push and release events.
@@ -27,7 +28,46 @@ jobs:
       - name: Install dependencies
         run: pip install pre-commit
       - name: Run pre-commit
-        run: pre-commit run --all-files
+        run: SKIP=license-headers pre-commit run --all-files
+
+  license-headers:
+    if: github.event_name == 'push' || github.event_name == 'pull_request'
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@1af3b93b6815bc44a9784bd300feb67ff0d1eeb3 # v6.0.0
+        with:
+          fetch-depth: 0
+      - uses: actions/setup-python@a309ff8b426b58ec0e2a45f0f869d46889d02405 # v6.2.0
+        with:
+          python-version: "3.14.3"
+      - run: pip install pre-commit
+
+      - name: Run pre-commit on changed files
+        run: |
+          if [ "${{ github.event_name }}" = "pull_request" ]; then
+            BASE_REF="${{ github.event.pull_request.base.sha }}"
+          else
+            BASE_REF="${{ github.event.before }}"
+          fi
+
+          if [ -z "$BASE_REF" ] || [ "$BASE_REF" = "0000000000000000000000000000000000000000" ]; then
+            echo "No valid base ref; skipping."
+            exit 0
+          fi
+
+          if ! git cat-file -e "$BASE_REF^{commit}" 2>/dev/null; then
+            echo "$BASE_REF is not available locally; falling back to HEAD^."
+            BASE_REF="HEAD^"
+          fi
+
+          CHANGED_FILES=$(git diff --name-only --diff-filter=AM "$BASE_REF" HEAD)
+
+          if [ -z "$CHANGED_FILES" ]; then
+            echo "No added or modified files; skipping."
+            exit 0
+          fi
+
+          pre-commit run license-headers --files $CHANGED_FILES
 
   django-check:
     runs-on: ubuntu-latest

.pre-commit-config.yaml

@@ -1,3 +1,5 @@
+# SPDX-License-Identifier: FSL-1.1-MIT
+
 # See https://pre-commit.com for more information
 # See https://pre-commit.com/hooks.html for more hooks
 repos:
@@ -14,3 +16,18 @@ repos:
         types: [python]
       - id: check-yaml
       - id: check-added-large-files
+
+  - repo: https://github.com/Lucas-C/pre-commit-hooks
+    rev: v1.5.5
+    hooks:
+      - id: insert-license
+        name: insert-license
+        alias: license-headers
+        files: \.(py|yaml|yml|md|sh|Dockerfile|ini)$
+        stages: [pre-commit]
+        args:
+          - --license-filepath
+          - LICENSE_HEADER.txt
+          - --comment-style
+          - "#"
+          - --no-extra-eol

LICENSE_HEADER.txt

@@ -0,0 +1 @@
+SPDX-License-Identifier: FSL-1.1-MIT