feat(.ai): agent memory retro skill

[marissahuysentruyt]

Description

⚠️ NICE-TO-HAVE PARALLEL MERGE ⚠️
Can be merged directly into feat-agnostic-ai-folder-stuff before or after the washing machine skills PR #6127 or the skills mindset PR #6139

Introduces a session-retrospective skill and "seed content" under .ai/memory/ so agents can capture persistent lessons learned (especially after user corrections) instead of losing them across sessions. The intent of this skill is for agents to self-document, learn from their mistakes, and share that learning across team members' agents.

Motivation and context

AGENTS.md at the repo root already tells agents to read .ai/memory/ when present. This skill operationalizes how to write and maintain those files, and provides two files that were created during the testing of this skill so the directory is not empty and the format is obvious.

Related issue(s)

• fixes [Issue Number]

Screenshots (if appropriate)

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Author's checklist

• I have read the CONTRIBUTING and PULL_REQUESTS documents.
• I have reviewed at the Accessibility Practices for this feature, see: Aria Practices
• I have added automated tests to cover my changes.
• I have included a well-written changeset if my change needs to be published.
• I have included updated documentation if my change required it.

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Reviewer's checklist

• Includes a Github Issue with appropriate flag or Jira ticket number without a link
• Includes thoughtfully written changeset if changes suggested include patch, minor, or major features
• Automated tests cover all use cases and follow best practices for writing
• Validated on all supported browsers
• All VRTs are approved before the author can update Golden Hash

Manual review test cases

• Read session-retrospective/SKILL.md to confirm it's clear.
• Confirm .ai/README.md entry matches the skill name and paths.
• Skim agnostic-lessons.md and css-styling-lessons.md for accuracy and tone (actionable, scannable).
• Optional: resolve lessons.md vs <descriptor>-lessons.md wording in the skill for consistency.

Device review

• Did it pass in Desktop?
• Did it pass in (emulated) Mobile?
• Did it pass in (emulated) iPad?

Accessibility testing checklist

• Keyboard
  Documentation only.

• Screen reader
  Documentation only.

[changeset-bot]

⚠️ No Changeset found

Latest commit: 735507a

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[github-actions]

📚 Branch Preview Links

• Documentation Site (first-gen)
• Storybook (first-gen)
• Storybook (second-gen)

🔍 First Generation Visual Regression Test Results

When a visual regression test fails (or has previously failed while working on this branch), its results can be found in the following URLs:

• Spectrum | Light | Medium | LTR
• Spectrum | Dark | Large | RTL
• Express | Light | Medium | LTR
• Express | Dark | Large | RTL
• Spectrum-two | Light | Medium | LTR
• Spectrum-two | Dark | Large | RTL
• High Contrast Mode | Medium | LTR

Deployed to Azure Blob Storage: pr-6138

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