chore: improve greet workflow and add YAML linting

- Add timeout-minutes and project-specific guidance to greet.yml
- Add links to CONTRIBUTING.md and CODE_OF_CONDUCT.md
- Add uvx yamllint command to docs and CONTRIBUTING.md
- Add .yamllint.yml config for GitHub Actions workflows

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

Author: sjnims

.github/workflows/greet.yml

@@ -17,22 +17,29 @@ jobs:
     # Skip bot accounts to avoid greeting automated tools
     if: github.actor != 'dependabot[bot]' && github.actor != 'claude[bot]'
     runs-on: ubuntu-latest
+    timeout-minutes: 5
     permissions:
       issues: write
       pull-requests: write
     steps:
       - uses: actions/first-interaction@1c4688942c71f71d4f5502a26ea67c331730fa4d # v3.1.0
         with:
           issue_message: |
-            👋 Thanks for opening your first issue! We appreciate your contribution to plugin-dev.
+            Thanks for opening your first issue! 👋 We appreciate your contribution to plugin-dev.
 
-            Please make sure you've provided all the requested information in the issue template. Our maintainers will review this soon.
+            **Resources:**
+            - [Contributing Guide](CONTRIBUTING.md)
+            - [Code of Conduct](CODE_OF_CONDUCT.md)
+
+            Please ensure you've provided all the requested information in the issue template.
+            Our maintainers will review this soon!
           pr_message: |
-            🎉 Thanks for opening your first pull request! We appreciate your contribution to plugin-dev.
+            Thanks for opening your first pull request! 🎉 We appreciate your contribution to plugin-dev.
 
-            Please make sure:
-            - [ ] You've filled out the PR template completely
-            - [ ] All markdown is properly linted
-            - [ ] You've tested the changes locally
+            **Before merge, please ensure:**
+            - [ ] You've read our [Contributing Guide](CONTRIBUTING.md)
+            - [ ] All markdown is properly linted (`markdownlint '**/*.md' --ignore node_modules`)
+            - [ ] Shell scripts pass validation (`shellcheck plugins/plugin-dev/skills/*/scripts/*.sh`)
+            - [ ] You've tested the changes locally with `claude --plugin-dir plugins/plugin-dev`
 
             A maintainer will review your PR soon. Feel free to ask questions if you need help!

.yamllint.yml

@@ -0,0 +1,19 @@
+---
+# yamllint configuration for GitHub Actions workflows
+
+extends: default
+
+rules:
+  # GitHub Actions workflows don't require document start
+  document-start: disable
+
+  # Disable line-length - GHA workflows have long inline scripts and URLs
+  line-length: disable
+
+  # GHA uses truthy triggers like `on: push` which is fine
+  truthy:
+    allowed-values: ["true", "false", "on"]
+
+  # Single space before comments is acceptable
+  comments:
+    min-spaces-from-content: 1

CLAUDE.md

@@ -55,6 +55,9 @@ markdownlint '**/*.md' --ignore node_modules
 
 # Lint shell scripts
 shellcheck plugins/plugin-dev/skills/*/scripts/*.sh
+
+# Lint YAML files
+uvx yamllint .github/workflows/
 ```
 
 ## Key Conventions

CONTRIBUTING.md

@@ -143,6 +143,15 @@ markdownlint '**/*.md' --ignore node_modules
 markdownlint '**/*.md' --ignore node_modules --fix
 ```
 
+### YAML Linting
+
+GitHub Actions workflows must pass YAML linting:
+
+```bash
+# Lint workflow files
+uvx yamllint .github/workflows/
+```
+
 **Style Rules** (see `.markdownlint.json`):
 
 - Use ATX-style headers (`#`, `##`, `###`)