Add Claude Code skill for managing supported versions

[rhoerr]

Summary

• Adds a Claude Code skill (.claude/skills/add-supported-version/SKILL.md) that guides the process of adding new Mage-OS or Magento Open Source releases to the supported-version CI matrix

What this skill does

When invoked (via /add-supported-version or natural language like "add version 2.2.2"), it walks through:

1. Reading current state from individual.json and composite.json
2. Updating the previous version's EOL date
3. Adding the new version entry with correct service versions, release date, and EOL (release + 3 years)
4. Updating composite.json range, default, and next entries
5. Adding a test case to get-currently-supported.spec.ts
6. Building dist and running tests
7. Git workflow (branch, commit, push)
8. Creating a PR to upstream

Key behaviors encoded

• Previous version identification: Finds the highest patch in the same minor line (e.g., 2.2.1 is previous to 2.2.2, not 2.2.0)
• Scope isolation: New minor lines (e.g., 2.3.0) don't touch other minor lines' EOL dates
• Composite range dates: Range release dates are preserved (they reflect when the minor line first shipped)
• Project differences: Handles both Mage-OS (with upstream field, X.Y.Z format) and Magento Open Source (X.Y.Z-pN format)

Test plan

• Tested with 3 eval scenarios: Mage-OS patch, Magento patch, new minor line
• Iteration 1: 29/32 assertions passed (91%)
• Iteration 2: 32/32 assertions passed (100%) after skill refinements
• Used successfully in production to add Mage-OS 2.2.2 (PR Add supported version for Mage-OS 2.2.2 #317)

🤖 Generated with Claude Code