chore(agents): add managing-atomic-components Agent Skill

[fbeaudoincoveo]

Context

This PR is a follow up to:

• chore: rework AGENTS.md files #7133
• chore(agents): simplify AGENTS.md #7180
• chore(agents): add atomic-unit-testing Agent Skill #7186

What's Added

A new maintaining-atomic-components Agent Skill that incorporates all of the information and patterns from the atomic.instructions.md.

What's Removed

• The atomic.instructions.md file has been deleted
• Redundant information about component directory structure has been removed from the Atomic AGENTS.md

What's Been Intentionally Being Kept (For Now)

• The generate-component.mjs script and related generate-component-templates folder. Reasoning: those might still be useful for manually creating the boilerplate. However, according to my own experimentations it seems like models are now sufficiently capable to no longer need to use these scripts at all... in fact, the model will often simply delete the generated placeholders files and re-create them from scratch rather than modifying them. I'm open to just deleting if we find that they're useless, though. They might just be maintenance burden.
• References to atomic.instructions.md in .prompt.md files, .agent.md files, and .instructions.md files other than general.instructions.md. Reasoning: these context files are doomed anyways. No use updating them.

Next Steps

• Get rid of all remaining .instructions.md files
• Get rid of all obsolete .agent.md files
• Get rid of all obsolete Agent Skills
• Rework remaining .agent.md files into Agent Skills
• Remove all remaining agent.md files
  Rename .claude folder to .agents, update opencode.json config, and update all references in AGENTS.md and Agent Skills

https://coveord.atlassian.net/browse/KIT-5490

[github-actions]

🔗 Scratch Orgs ready to test this PR:

• ✅ LWS Enabled: Open Org
• ✅ LWS Disabled: Open Org

[Copilot]

Pull request overview

This PR continues the agent-instructions cleanup by migrating Atomic component conventions from the deleted .github/instructions/atomic.instructions.md into a dedicated Agent Skill, while removing redundant structure details from Atomic’s AGENTS.md.

Changes:

• Added a new Atomic component conventions Agent Skill under .claude/skills/* (skill + detailed implementation reference).
• Removed the legacy .github/instructions/atomic.instructions.md and cleaned up some references to it.
• Simplified Atomic package docs by removing redundant component folder structure from packages/atomic/AGENTS.md.

Reviewed changes

Copilot reviewed 6 out of 6 changed files in this pull request and generated 1 comment.

Show a summary per file

File	Description
packages/atomic/AGENTS.md	Removes redundant Atomic component folder structure section.
packages/atomic-legacy/README.md	Drops reference to the deleted Stencil→Lit instruction file.
.github/instructions/general.instructions.md	Removes atomic.instructions.md reference, but still contains examples pointing to now-missing instruction files.
.github/instructions/atomic.instructions.md	Deleted; content moved into an Agent Skill.
.claude/skills/managing-atomic-components/SKILL.md	New skill containing Atomic component structure/conventions.
.claude/skills/managing-atomic-components/references/component-implementation.md	New detailed reference for Atomic Lit component implementation patterns.

Comments suppressed due to low confidence (1)

.github/instructions/general.instructions.md:15

• The instruction hierarchy examples reference tests-atomic.instructions.md and an “Atomic package specifies Tailwind…” package-specific instruction, but there is no .github/instructions/tests-atomic.instructions.md (and atomic.instructions.md was deleted in this PR). This leaves readers with dead/incorrect pointers.

Consider updating these examples to point to the new Agent Skills (e.g., atomic-unit-testing, managing-atomic-components) or to existing instruction files, and/or add a small stub/redirect file if you want to keep legacy links working (there are still multiple references to atomic.instructions.md elsewhere in the repo).

1. Workspace prompts (e.g., `workspace-prompts.instructions.md` for `.github/prompts/*.prompt.md`)
2. Package-specific (e.g., `tests-atomic.instructions.md`)
3. File-type specific (e.g., `general.typescript.instructions.md`)
4. General (this file)
5. Language/framework defaults

**Example:** Atomic package specifies Tailwind for Lit components → follow that, not general styling preferences.