Add pre-commit hook to prevent direct commits to the main branch

.pre-commit-config.yaml

@@ -1,6 +1,12 @@
 repos:
 - repo: local
   hooks:
+  - id: no-commit-to-main
+    name: Don't commit to main branch
+    entry: sh -c 'if [ "$(git rev-parse --abbrev-ref HEAD)" = "main" ]; then echo "Direct commits to main branch are not allowed!"; exit 1; fi'
+    language: system
+    pass_filenames: false
+    always_run: true
   - id: test-ui
     name: Test Frontend
     entry: just test-frontend