Add agent skills for AI coding

[yihao03]

used opencode to read devGuide and generated relevant skills

What is the purpose of this pull request?

• Documentation update
• Bug fix
• Feature addition or enhancement
• Code maintenance
• DevOps
• Improve developer experience
• Others, please explain:

Overview of changes:
This PR serves as part of the effort to develop an AI workflow for development.

We opted to use the open source SKILL.md standard as it is provider agnostic and has good community support.
Therefore we could adopt mainstream and popular workflows developed by others without being restricted to a specific provider (e.g. ClaudeCode).

Useful references in creating skills:

• Claude's documentation
• OpenCode's documentation

Anything you'd like to highlight/discuss:

Testing instructions:
Use AI Coding tools like OpenCode/ClaudeCode to start writing code. Check if the skills are being picked up
correctly and performs as desired

Proposed commit message: (wrap lines at 72 characters)
Add Agent Skills.

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Checklist: ☑️

• Updated the documentation for feature additions and enhancements
• Added tests for bug fixes or features
• Linked all related issues
• No unrelated changes

---

Reviewer checklist:

Indicate the SEMVER impact of the PR:

• Major (when you make incompatible API changes)
• Minor (when you add functionality in a backward compatible manner)
• Patch (when you make backward compatible bug fixes)

At the end of the review, please label the PR with the appropriate label: r.Major, r.Minor, r.Patch.

Breaking change release note preparation (if applicable):

• To be included in the release note for any feature that is made obsolete/breaking

Give a brief explanation note about:

• what was the old feature that was made obsolete
• any replacement feature (if any), and
• how the author should modify his website to migrate from the old feature to the replacement feature (if possible).

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 71.76%. Comparing base (0f70952) to head (9c52707).

Additional details and impacted files

@@           Coverage Diff           @@
##           master    #2804   +/-   ##
=======================================
  Coverage   71.76%   71.76%           
=======================================
  Files         134      134           
  Lines        7316     7316           
  Branches     1614     1556   -58     
=======================================
  Hits         5250     5250           
+ Misses       2020     1938   -82     
- Partials       46      128   +82     

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