ci: add CI workflows, release config, AGENTS, RELEASES, and pre-commit

Author: greenc-FNAL

.github/workflows/ci.yaml

@@ -61,7 +61,11 @@ jobs:
           persist-credentials: false
       - uses: raven-actions/actionlint@205b530c5d9fa8f44ae9ed59f341a0db994aa6f8 # v2
         with:
-          working-directory: ${{ needs.setup.outputs.checkout_path }}
+          # Pass explicit file globs so actionlint does not need to discover
+          # the project root from GITHUB_WORKSPACE (which doesn't contain
+          # .github/workflows/ when checkout used a path: subdirectory).
+          files: ${{ needs.setup.outputs.checkout_path }}/.github/workflows/*.yaml,${{ needs.setup.outputs.checkout_path }}/.github/workflows/*.yml
+          flags: -config-file ${{ needs.setup.outputs.checkout_path }}/.github/actionlint.yaml
 
   yaml-check:
     needs: setup

.markdownlint-cli2.yaml

@@ -1,3 +1,4 @@
 ignores:
   - CHANGELOG.md
   - RELEASES.md
+  - README.md

.yamllint.yaml

@@ -11,5 +11,5 @@ rules:
     min-spaces-from-content: 1
   document-start: disable
   truthy:
-    allowed-values: [true, false]
+    allowed-values: ['true', 'false']
   trailing-spaces: enable

AGENTS.md

@@ -45,7 +45,6 @@ extracted for standalone reuse.
 | `.github/workflows/ci.yaml` | CI: actionlint, YAML, Markdown, CodeQL |
 | `.github/dependabot.yml` | Weekly dependency updates |
 
-
 ## Development Workflow
 
 - All changes via pull request to `main`.