FEC-326: Add AI agent configuration and shared skills

[misama-ct]

Summary

• Add AGENTS.md and CLAUDE.md to every package, template, and app directory (34 directories) providing per-package context for AI coding agents
• Install 7 shared agent skills (repo-healthcheck, repo-maintenance, renovate-review, renovate-migrate, pr-review-navigator, security-auditor, remember) with symlinks for Claude Code, Continue, and Goose
• Add root AGENTS.md documenting repo architecture, data flow, build pipeline, common workflows, conventions, and gotchas
• Add root CLAUDE.md with MCP server references, hook config, and skill inventory
• Configure .mcp.json with 4 MCP servers (commercetools-docs, context7, playwright, sequential-thinking)
• Configure .claude/settings.json with Prettier post-write hook
• Migrate templates from ESLint legacy .eslintrc.js to ESLint 9 flat config format
• Clean up unnecessary jest-runner-eslint pnpm override in templates
• Update template lockfiles for ESLint ^9.0.0

Test plan

• pnpm install succeeds
• pnpm build succeeds
• All 21 symlinks (7 × 3 agent platforms) resolve to valid targets
• All SKILL.md files are present and non-empty
• .mcp.json and .claude/settings.json are valid JSON
• All 34 package directories have both AGENTS.md and CLAUDE.md
• skills-lock.json is valid with SHA-256 hashes for all 7 skills

[changeset-bot]

⚠️ No Changeset found

Latest commit: 62cd165

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[vercel]

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Project	Deployment	Actions	Updated (UTC)
mc-app-kit-playground	Ready	Preview, Comment	Apr 9, 2026 7:39am
merchant-center-application-kit-components-playground	Ready	Preview, Comment	Apr 9, 2026 7:39am

[codecov-commenter]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 72.61%. Comparing base (ee05b63) to head (62cd165).
⚠️ Report is 1 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #3962      +/-   ##
==========================================
+ Coverage   71.91%   72.61%   +0.70%     
==========================================
  Files         263      264       +1     
  Lines        6801     7016     +215     
  Branches     2104     2192      +88     
==========================================
+ Hits         4891     5095     +204     
- Misses       1889     1898       +9     
- Partials       21       23       +2     

Components	Coverage Δ
Application Components	81.18% <ø> (ø)
Application Shell	74.54% <ø> (ø)
Application Shell Connectors	77.54% <ø> (ø)

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