Fix GitHub Actions welcome workflow using best practices

Problem Analysis:
- Original workflow used complex GitHub search API causing rate limiting issues
- Custom first-time contributor detection was unreliable and fragile
- Used pull_request instead of pull_request_target for PRs (security issue)
- Complex github-script logic prone to failures

Solution Implemented:
- Replaced custom logic with GitHub's official actions/first-interaction@v1
- Changed to pull_request_target for PR security and reliability
- Eliminated API rate limiting issues by removing search calls
- Simplified permissions and workflow structure
- Added comprehensive welcome messages with community guidelines

Benefits:
- More reliable first-time contributor detection
- No rate limiting issues
- Better security with pull_request_target
- Easier to maintain using official GitHub action
- Consistent messaging across issues and PRs

Also included alternative implementation example using garg3133/welcome-new-contributors@v1.2

.github/workflows/welcome-new-contributors-alternative.yml.example

@@ -0,0 +1,102 @@
+# Alternative Welcome Workflow using third-party action
+# This is an example implementation using garg3133/welcome-new-contributors
+# Rename to .yml and adjust the main workflow if you prefer this approach
+
+name: Welcome New Contributors (Alternative)
+
+on:
+  issues:
+    types: [opened]
+  pull_request_target:
+    types: [opened]
+
+jobs:
+  welcome:
+    runs-on: ubuntu-latest
+    permissions:
+      issues: write
+      pull-requests: write
+    
+    steps:
+      - name: Welcome first-time contributors
+        uses: garg3133/welcome-new-contributors@v1.2
+        with:
+          token: ${{ secrets.GITHUB_TOKEN }}
+          issue-message: |
+            👋 **Welcome to the Claude Code Agents project, @contributor_name!**
+
+            Thank you for opening your first issue! We appreciate your interest in contributing to our collection of specialized subagents.
+
+            ## 📋 Community Guidelines
+
+            Before we proceed, please take a moment to review our community standards:
+
+            - 📖 **[Code of Conduct](.github/CODE_OF_CONDUCT.md)** - Our community standards and behavioral expectations
+            - 🤝 **[Contributing Guidelines](.github/CONTRIBUTING.md)** - How to contribute effectively
+            - 💬 **[GitHub Discussions](https://github.com/wshobson/agents/discussions)** - For questions and general discussion
+
+            ## 🛡️ Community Values
+
+            We maintain a **respectful, inclusive, and professional environment**. Our community does not tolerate:
+            - Hate speech, discrimination, or harassment
+            - Personal attacks or inflammatory language  
+            - Spam, trolling, or off-topic content
+            - Any content that violates our Code of Conduct
+
+            ## ✅ What Makes a Great Issue
+
+            - Clear, specific problem descriptions
+            - Steps to reproduce (for bugs) 
+            - Constructive feature requests with use cases
+            - Professional, respectful language
+
+            ## 🚀 Next Steps
+
+            A maintainer will review your issue soon. Please feel free to:
+            - Add any additional context if needed
+            - Respond to questions from maintainers
+            - Join our [Discussions](https://github.com/wshobson/agents/discussions)
+
+            Thank you for helping make this project better! 🎉
+
+          pr-message: |
+            👋 **Welcome to the Claude Code Agents project, @contributor_name!**
+
+            Thank you for opening your first pull request! We appreciate your interest in contributing to our collection of specialized subagents.
+
+            ## 📋 Community Guidelines
+
+            Before we proceed, please take a moment to review our community standards:
+
+            - 📖 **[Code of Conduct](.github/CODE_OF_CONDUCT.md)** - Our community standards and behavioral expectations
+            - 🤝 **[Contributing Guidelines](.github/CONTRIBUTING.md)** - How to contribute effectively
+            - 💬 **[GitHub Discussions](https://github.com/wshobson/agents/discussions)** - For questions and general discussion
+
+            ## 🛡️ Community Values
+
+            We maintain a **respectful, inclusive, and professional environment**. Our community does not tolerate:
+            - Hate speech, discrimination, or harassment
+            - Personal attacks or inflammatory language  
+            - Spam, trolling, or off-topic content
+            - Any content that violates our Code of Conduct
+
+            ## ✅ What Makes a Great Pull Request
+
+            - Well-documented changes with clear descriptions
+            - Following existing code style and conventions
+            - Clear, descriptive commit messages
+            - Addressing a specific issue or improvement
+            - Including tests or examples where appropriate
+
+            ## 🚀 Next Steps
+
+            A maintainer will review your pull request soon. Please feel free to:
+            - Add any additional context about your changes
+            - Respond to feedback and questions from maintainers
+            - Join our [Discussions](https://github.com/wshobson/agents/discussions)
+
+            Thank you for helping make this project better! 🎉
+
+          # Optional: Add labels to first-time contributor issues/PRs
+          issue-labels: 'first-time-contributor, needs-review'
+          pr-labels: 'first-time-contributor, needs-review'