refactor(skills): apply simplify-pass cleanups across the stack

[k11kirky]

Problem

Several small pieces of logic were duplicated or misplaced across the skills feature, making it harder to maintain and extend. Specifically: the "already installed locally" marking was coupled to the team skills fetch, stripFrontmatter existed only in the UI package, error-handling patterns were repeated inline across many components, and the card row layout was copy-pasted across three different list surfaces.

Changes

Decouple local-install marking from the team skills fetch
listTeamSkills no longer accepts localSkillNames and no longer marks skills as installed. A new pure function markInstalledTeamSkills handles that separately. useTeamSkills now fetches the team listing once and applies markInstalledTeamSkills in a useMemo, so local skill changes never trigger a refetch of the remote listing. The query key structure is also cleaned up with a shared teamSkillsKeys.all root so invalidations are consistent.

Move stripFrontmatter to @posthog/shared
The UI-local stripFrontmatter.ts is deleted. A CRLF-aware version now lives in packages/shared/src/skills.ts and is exported from the package index. All consumers (SkillDetailPanel, MarketplaceSkillPanel, TeamSkillDetailPanel, the workspace-server export path) import from @posthog/shared.

Centralise skill error helpers
A new skillErrors.ts module exposes isSkillExistsError and skillErrorDescription. All the scattered error instanceof Error ? error.message : "" / .includes("already exists") patterns across SkillDetailPanel, TeamSkillDetailPanel, MarketplaceSkillPanel, SkillFileEditor, SkillManifestEditor, NewSkillDialog, and SkillFileEditor are replaced with calls to these helpers.

Extract SkillListCard shared component
The identical card-row markup (icon box, title/subtitle text block, trailing slot, selection highlight) was duplicated in SkillCard, TeamSkillsSection, and MarketplaceBrowse. It is now a single SkillListCard component with icon, title, subtitle, isSelected, onClick, and trailing props.

Extract ReplaceSkillDialog shared component
The confirm-overwrite AlertDialog was duplicated in MarketplaceSkillPanel, TeamSkillDetailPanel, and SkillDetailPanel. It is now a single ReplaceSkillDialog component parameterised by skillName, verb ("Reinstalling" / "Importing"), and onConfirm.

Consolidate getUserSkillsDir and isProbablyText
Both helpers were defined inline in multiple workspace-server files. They now live in skill-discovery.ts and are imported wherever needed, removing the repeated os.homedir() path construction.

Parallelise file I/O in the workspace server
Sequential for loops in mirrorUserSkillsToCodex, exportSkill, and installSkill are replaced with Promise.all calls.

Move installsFormatter to useMarketplace.ts
The Intl.NumberFormat instance was duplicated in MarketplaceBrowse and MarketplaceSkillPanel; it is now exported once from useMarketplace.ts.

Remove unused resolveLlmSkill API method
resolveLlmSkill and its LlmSkillResolveResponse type are removed from the API client as they are no longer called anywhere.

How did you test this?

• Updated unit tests for TeamSkillsService.listTeamSkills to reflect the removed localSkillNames parameter.
• Added a new markInstalledTeamSkills unit test covering name-based matching and unrelated local names.
• Existing tests for publishSkill and other service methods continue to pass.

Automatic notifications

• Publish to changelog?
• Alert Sales and Marketing teams?

[k11kirky]

• refactor(skills): apply simplify-pass cleanups across the stack #2612 👈 (View in Graphite)
• feat(skills): Codex unification — bring your skills, use them anywhere #2611
• feat(skills): publish skills to the team and install team skills locally #2610
• feat(skills): PostHog cloud team skills — read path #2609
• feat(skills): skills.sh marketplace browse and install #2608
• feat(skills): validation and shadowing signals #2607
• feat(skills): live refresh from the filesystem #2606
• feat(skills): create, edit, and delete user and repo skills #2605
• feat(skills): render full skill directories #2604
• main

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[github-actions]

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[greptile-apps]

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[k11kirky]

Merge activity

• Jun 12, 11:31 AM UTC: A user started a stack merge that includes this pull request via Graphite.
• Jun 12, 11:32 AM UTC: Graphite couldn't merge this pull request because a downstack PR feat(skills): create, edit, and delete user and repo skills #2605 failed to merge.
• Jun 12, 11:54 AM UTC: A user started a stack merge that includes this pull request via Graphite.
• Jun 12, 1:12 PM UTC: Graphite rebased this pull request as part of a merge.
• Jun 12, 1:24 PM UTC: @k11kirky merged this pull request with Graphite.