Follow-up: research and improve the Epic Stack catch-up cloud-agent skill

[cursor]

Parent issue: #23

Not blocking. Do not start this instead of packages 2–7 or the Playwright CI cache issue. Iterate the skill as those packages land; use this issue to research and fold improvements in later.

Goal

Improve .cursor/skills/epic-stack-catch-up/SKILL.md (and the pointer rule .cursor/rules/epic-stack-catch-up.mdc) using what we learn from the rest of the catch-up list plus a bit of outside research.

The first version of the skill was written from package 1/7 (#24 / PR #31) only: RR 7.18 typegen Info removal (one-time), loader url/pattern args, Playwright sprite.svg collection, and the browser-install hang.

Do this (later, or in small follow-up PRs)

After each catch-up PR (or in one pass after several):

1. Add only pitfalls that actually happened (Sentry hidden maps, LiteFS replica cache, Express 5 path matching, Vite 7 / Vitest 4, auto-routes + dashboard+ moves). Do not speculate a novel architecture.
2. Keep the skill short enough that a cheap Cloud Agent will follow it. Prefer bullets and “do not” lists over essays.
3. Research (when you pick this issue up):
   • Playwright’s current GitHub Actions browser-cache guidance vs what we shipped in the CI issue
   • Whether Epic Stack later added browser caching (they had none as of Aug 2026)
   • Cursor Cloud Agent skill/rule patterns that reliably attach on GitHub-issue runs
4. PR into dev. Skill/rule files only unless a one-line pointer in the parent issue comment is useful.

Files allowed

• .cursor/skills/epic-stack-catch-up/SKILL.md
• .cursor/rules/epic-stack-catch-up.mdc
• Optionally a short comment on Epic Stack catch-up: tracking #23 pointing at the updated skill

Do not

• Do not block packages 2–7 on this
• Do not dump Epic Stack’s skills markdown into this repo (still in Epic Stack catch-up: tracking #23’s skip list)
• Do not bump dependencies

Acceptance

• Skill still matches “one child issue, branch origin/dev, PR into dev, merge then staging smoke”
• New pitfalls from completed packages are recorded
• PR targets dev

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Not in the critical path. Implement when convenient.