feat: add actionlint to CI and pre-commit for workflow validation

Add actionlint as a step in the Code Quality CI workflow using the
SHA-pinned raven-actions/actionlint action (v2.1.2, actionlint 1.7.12).
Add .pre-commit-config.yaml with markdownlint and actionlint hooks.
Update CONTRIBUTING.md with pre-commit setup instructions.

Ref: RHAIENG-4067

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: tarun-etikala

.github/workflows/code-quality.yml

@@ -41,3 +41,8 @@ jobs:
         uses: DavidAnson/markdownlint-cli2-action@ce4853d43830c74c1753b39f3cf40f71c2031eb9  # v23.0.0
         with:
           globs: "**/*.md"
+
+      - name: Actionlint
+        uses: raven-actions/actionlint@205b530c5d9fa8f44ae9ed59f341a0db994aa6f8  # v2.1.2
+        with:
+          version: 1.7.12

.pre-commit-config.yaml

@@ -0,0 +1,10 @@
+repos:
+  - repo: https://github.com/DavidAnson/markdownlint-cli2
+    rev: v0.22.1
+    hooks:
+      - id: markdownlint-cli2
+
+  - repo: https://github.com/rhysd/actionlint
+    rev: v1.7.12
+    hooks:
+      - id: actionlint

CONTRIBUTING.md

@@ -16,31 +16,40 @@ Before submitting, please read our [Code of Conduct](CODE_OF_CONDUCT.md). By par
 
 ## Linting and formatting
 
-This project uses [ruff](https://docs.astral.sh/ruff/) for Python linting and formatting, and [markdownlint](https://github.com/DavidAnson/markdownlint) for Markdown linting. Both run as blocking CI checks on all pull requests via the `Code Quality` workflow.
+This project uses [ruff](https://docs.astral.sh/ruff/) (Python), [markdownlint](https://github.com/DavidAnson/markdownlint) (Markdown), and [actionlint](https://github.com/rhysd/actionlint) (GitHub Actions workflows). All three run as blocking CI checks on every pull request via the `Code Quality` workflow.
 
-### Python (ruff)
+Markdownlint and actionlint are configured as [pre-commit](https://pre-commit.com/) hooks. Set up once and they run automatically on every commit:
 
-Run locally before pushing:
+```bash
+uv tool install pre-commit
+pre-commit install
+```
+
+To run all hooks manually against the entire repo:
 
 ```bash
-uv tool install ruff==0.15.11
-ruff check .          # lint
-ruff format --check . # format check
-ruff format .         # auto-format
+pre-commit run --all-files
 ```
 
-Configuration is in [`ruff.toml`](ruff.toml) at the repo root.
+To run a specific linter:
 
-### Markdown (markdownlint)
+```bash
+pre-commit run markdownlint-cli2 --all-files  # Markdown lint
+pre-commit run actionlint --all-files         # GitHub Actions workflow lint
+```
+
+### Python (ruff)
 
 Run locally before pushing:
 
 ```bash
-npx markdownlint-cli2@0.22.1 "**/*.md"          # lint
-npx markdownlint-cli2@0.22.1 --fix "**/*.md"    # auto-fix
+uv tool install ruff==0.15.11
+ruff check .          # lint
+ruff format --check . # format check
+ruff format .         # auto-format
 ```
 
-Configuration is in [`.markdownlint.jsonc`](.markdownlint.jsonc) (rules) and [`.markdownlint-cli2.yaml`](.markdownlint-cli2.yaml) (ignored paths) at the repo root.
+Configuration files: [`ruff.toml`](ruff.toml), [`.markdownlint.jsonc`](.markdownlint.jsonc), [`.markdownlint-cli2.yaml`](.markdownlint-cli2.yaml), [`.pre-commit-config.yaml`](.pre-commit-config.yaml).
 
 ## Commit message conventions