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## Summary

Motivated by #1297 the `.yarnrc` template fix revealed that `vp create` had no e2e test coverage, making it easy for template bugs to ship undetected.

- Add a new GitHub Actions workflow (`test-vp-create.yml`) that e2e tests `vp create` across all 3 built-in templates (monorepo, application, library) and all 4 package managers (pnpm, npm, yarn, bun) — 12 test combinations
- Fix bun monorepo migration writing empty `catalog` with dangling `catalog:` references when using `file:` protocol
- Fix yarn standalone projects missing `.yarnrc.yml` with `nodeLinker: node-modules`
- Pass `--no-frozen-lockfile` from `vp create` in CI so yarn Berry can create fresh lockfiles

## Changes

### New: `vp create` e2e test workflow

- Uses the same tgz-packaging approach as ecosystem-ci: build → pack → install vp from tgz → run `vp create` with `VP_OVERRIDE_PACKAGES`/`VP_VERSION` pointing to local packages
- Each test verifies: project structure, correct lockfile, `vite-plus@0.0.0` installed, `vp check`, and build/test commands
- Monorepo tests run `vp run ready` twice and assert 100% cache hit on the second run
- Triggered on push to main (path-filtered), PRs with `test: create-e2e` label, or create-related file changes

### Fix: bun monorepo catalog with `file:` protocol

- `rewriteBunCatalog()` unconditionally set all overrides to `catalog:` but skipped `file:` entries from the catalog, leaving unresolvable references
- Now uses `file:` paths directly in overrides when the value starts with `file:`

### Fix: yarn standalone projects

- `rewriteYarnrcYml()` now sets `nodeLinker: node-modules` when absent (yarn 4 defaults to PnP)
- `rewriteStandaloneProject()` now calls `rewriteYarnrcYml()` for yarn projects (previously only called for monorepos)
- `vp create` passes `--no-frozen-lockfile` to `vp install` in CI environments

## Test plan

- [x] All 12 matrix jobs pass in CI (3 templates × 4 package managers)
- [x] Existing migration tests pass (`vp test run packages/cli/src/migration/`)
- [x] New `bun-catalog-file-protocol.spec.ts` test verifies the bun override fix

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