Add yamllint, ansible-lint, and a syntax check

scripts/check.sh runs all three and CI calls the same script. ansible.cfg keeps Ansible's temp and Galaxy caches inside the checkout so the checks work when $HOME is read-only.

.pre-commit-config.yaml

@@ -0,0 +1,20 @@
+---
+# Local hook, same checks as CI. Enable with:
+#   pre-commit install
+repos:
+  - repo: https://github.com/pre-commit/pre-commit-hooks
+    rev: v4.6.0
+    hooks:
+      - id: trailing-whitespace
+      - id: end-of-file-fixer
+      - id: check-yaml
+        args: [--allow-multiple-documents]
+      - id: check-added-large-files
+  - repo: https://github.com/adrienverge/yamllint
+    rev: v1.35.1
+    hooks:
+      - id: yamllint
+  - repo: https://github.com/ansible/ansible-lint
+    rev: v24.7.0
+    hooks:
+      - id: ansible-lint