Addressed #7269

WHY are these changes introduced?

E2E tests currently share a single pre-existing dev store configured via E2E_STORE_FQDN. This causes:

• Shared state: earlier test failures can leave installed apps or modified config that affect later tests
• No isolation: tests can't run independently — one test's side effects leak into the next
• Fragile teardown: the old teardownApp silently skips steps, doesn't verify success, and a single failure blocks later cleanup

This PR also lays the foundation for parallel workers (future PR), where shared stores would be impossible since multiple tests run simultaneously.

WHAT is this pull request doing?

Per-test store isolation:

• Tests that need a dev store (app dev, hot reload, multi-config dev, toml-config dev) create a fresh store via browser automation on admin.shopify.com/store-create/organization/{orgId}
• Each test gets its own isolated store — no shared state between tests
• Store is created in test setup and cleaned up in teardown

Robust teardown with escalating retry (setup/teardown.ts):

Three independent phases — failure in one never blocks the next:

• Phase 1: Uninstall app from store (3 attempts)

  • Navigates to store admin /settings/apps, finds app by name, clicks uninstall
  • Verifies app is gone (checks immediately, reloads once if still visible)
  • Dismisses Dev Console panel via h2:has-text("Dev Console") → button[aria-label="hide"]

• Phase 2: Delete store (3 attempts)

  • Navigates to /settings/apps to check state
  • Detects if store already deleted (access_account redirect)
  • Verifies no apps installed via isStoreAppsEmpty (reloads once if stale)
  • Navigates to /settings/plan, clicks delete, checkbox, confirm
  • Verifies deletion via access_account URL

• Phase 3: Delete app from dashboard (3 attempts, always runs)

  • Searches dev dashboard with pagination for app by name
  • Clicks delete on settings page, confirms via button.critical[type="submit"]
  • Handles 500/502 errors: refreshIfPageError detects error pages and refreshes
  • Detects 404 after refresh as confirmation of successful deletion

Server error handling (setup/browser.ts):

• refreshIfPageError(page) detects 500/502 error pages and auto-refreshes
• Used across dashboard navigation, pagination, and app deletion retry loops

Tagged logging (setup/env.ts):

• createLogger(tag) produces [e2e][w0][browser], [e2e][w0][cli] format
• e2eSection() prints section headers: ----- SETUP: store ... -----, ----- TEARDOWN: app ... -----
• Clear per-attempt failure messages with specific reasons

Exported building blocks (setup/store.ts):

• uninstallAppFromStore(page, storeSlug, appName) → boolean
• deleteStore(page, storeSlug) → boolean
• isStoreAppsEmpty(page) → boolean (pure page checker, caller navigates)
• dismissDevConsole(page) → void

Files changed:

How to test your changes?

# Run all tests with debug output
DEBUG=1 pnpm --filter e2e exec playwright test

# Run headed to watch store creation/teardown
E2E_HEADED=1 DEBUG=1 pnpm --filter e2e exec playwright test

# Skip teardown for debugging (clean up manually after)
E2E_SKIP_CLEANUP=1 pnpm --filter e2e exec playwright test

Checklist

• I've considered possible cross-platform impacts (Mac, Linux, Windows)
• I've considered possible documentation changes
• I've considered analytics changes to measure impact
• The change is user-facing, so I've added a changelog entry with pnpm changeset add