feat: re-enable vp CLI caching

[fengmk2]

Summary

• Re-enable vp CLI caching that was temporarily disabled due to Windows Cannot find module 'which' issue (Windows runner failures with latest action version #10)
• Wire up SETUP_VP_FORCE_INSTALL env var to bypass cache restore, enabling CI to test both cached and fresh install paths
• Re-enable skipped unit tests for restoreVpCache and saveVpCache

Test plan

• CI passes on all platforms (ubuntu, macos, windows) with force-install: false (cached path)
• CI passes on all platforms with force-install: true (fresh install path)
• All 89 unit tests pass including previously-skipped cache tests

🤖 Generated with Claude Code

[Copilot]

Pull request overview

This PR re-enables caching for the Vite+ (vp) CLI in the setup-vp GitHub Action, adding a CI-controlled bypass to validate both cached and fresh install flows, and re-enabling the previously skipped cache unit tests.

Changes:

• Re-enable vp CLI cache restore/save logic, with an opt-out via SETUP_VP_FORCE_INSTALL=true.
• Wire SETUP_VP_FORCE_INSTALL to skip cache restore.
• Re-enable unit tests for restoreVpCache and saveVpCache.

Reviewed changes

Copilot reviewed 2 out of 3 changed files in this pull request and generated 1 comment.

File	Description
src/cache-vp.ts	Restores vp cache restore/save behavior and adds SETUP_VP_FORCE_INSTALL restore bypass.
src/cache-vp.test.ts	Un-skips and runs cache-related unit tests again.

Comments suppressed due to low confidence (1)

src/cache-vp.test.ts:90

• The new SETUP_VP_FORCE_INSTALL branch in restoreVpCache isn’t covered by unit tests, and these tests don’t explicitly clear/stub that env var. If a developer (or CI) runs tests with SETUP_VP_FORCE_INSTALL=true set, these cases will fail unexpectedly. Consider stubbing it to "false" in beforeEach, and add a test asserting that restoreVpCache skips the restore when SETUP_VP_FORCE_INSTALL is "true" (and that no cache restore call is made).

describe("restoreVpCache", () => {
  beforeEach(() => {
    vi.stubEnv("RUNNER_OS", "Linux");
    vi.stubEnv("HOME", "/home/runner");
  });

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[Copilot]

When SETUP_VP_FORCE_INSTALL is "true", this early return happens before computing/saving VpCachePrimaryKey. As a result, the post step’s saveVpCache() will always see an empty primary key and skip saving, so the “fresh install” path can never populate/warm the vp cache. If the intent is to bypass only the restore, consider still generating the cache key and calling saveState(State.VpCachePrimaryKey, ...) (and logging) while skipping just the restoreCache(...) call.

[fengmk2]

Files extracted from the cache cannot be used directly, let's wait for voidzero-dev/vite-plus#744

Error: Cannot find module 'which'
Require stack:
- C:\Users\runneradmin\.vite-plus\0.1.13\node_modules\.pnpm\cross-spawn@7.0.6\node_modules\cross-spawn\lib\util\resolveCommand.js
- C:\Users\runneradmin\.vite-plus\0.1.13\node_modules\.pnpm\cross-spawn@7.0.6\node_modules\cross-spawn\lib\parse.js
- C:\Users\runneradmin\.vite-plus\0.1.13\node_modules\.pnpm\cross-spawn@7.0.6\node_modules\cross-spawn\index.js