Coverage reporter installation fails in `vp test --coverage`

[eggplants]

Describe the bug

When I run vp test --coverage, it attempts to install @vitest/coverage-v8 by storybook, but it appears to be failing.

This wouldn't happen if the user had run vp add -D @vitest/coverage-v8 beforehand, but it seems to occur because vp doesn't set the PATH for pnpm.

It might be more user-friendly if vite+ displayed a prompt asking users to install a coverage provider for Vite in advance.

Reproduction

https://github.com/eggplants/michixa/tree/dada49e83965223ca89fe65d5045641ec7cc6128

Steps to reproduce

Launch Dev Container and run vp test --coverage.

System Info

❯ vp env current
VITE+ - The Unified Toolchain for the Web

Environment:
  Version  24.16.0
  Source   lts

Tool Paths:
  node  /root/.vite-plus/js_runtime/node/24.16.0/bin/node
  npm   /root/.vite-plus/js_runtime/node/24.16.0/bin/npm
  npx   /root/.vite-plus/js_runtime/node/24.16.0/bin/npx

❯ vp --version
VITE+ - The Unified Toolchain for the Web

vp v0.1.22

Local vite-plus:
  vite-plus  v0.1.22

Tools:
  vite             v8.0.11
  rolldown         v1.0.0
  vitest           v4.1.6
  oxfmt            v0.48.0
  oxlint           v1.63.0
  oxlint-tsgolint  v0.22.1
  tsdown           v0.22.0

Environment:
  Package manager  pnpm v11.2.2
  Node.js          v24.16.0

Used Package Manager

pnpm

Logs

❯ vp test --coverage
VITE+ - The Unified Toolchain for the Web

│
▲  No story files found for the specified pattern:
│  src/**/*.mdx
 MISSING DEPENDENCY  Cannot find dependency '@vitest/coverage-v8'

✔ Do you want to install @vitest/coverage-v8? … yes

⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯ Startup Error ⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯
Error: spawn pnpm ENOENT
    at Process.ChildProcess._handle.onexit (node:internal/child_process:287:19)
    at onErrorNT (node:internal/child_process:508:16)
    at processTicksAndRejections (node:internal/process/task_queues:90:21) {
  errno: -2,
  code: 'ENOENT',
  syscall: 'spawn pnpm',
  path: 'pnpm',
  spawnargs: [
    'install',
    '-D',
    '-w',
    '--prod=false',
    '@vitest/coverage-v8@0.1.22'
  ]
}

❯ vp add -D @vitest/coverage-v8          
[WARN] 2 deprecated subdependencies found: glob@11.1.0, source-map@0.8.0-beta.0
Packages: +26 -14
++++++++++++++++++++++++++--------------
Progress: resolved 764, reused 598, downloaded 0, added 0, done
[WARN] Issues with peer dependencies found. Run "pnpm peers check" to list them.

dependencies:
+ vitest <- @voidzero-dev/vite-plus-test 0.1.22

devDependencies:
+ @vitest/coverage-v8 4.1.7
- vitest 0.1.22

Done in 7s using pnpm v11.2.2

❯ vp test --coverage
...
 Test Files  8 passed (8)
      Tests  45 passed (45)
   Start at  19:02:50
   Duration  14.31s (transform 60ms, setup 20.60s, import 8.15s, tests 13.11s, environment 1.07s)

 % Coverage report from v8
...

❯ which pnpm
pnpm not found

❯ find /root/.vite-plus -name 'pnpm'                    
/root/.vite-plus/js_runtime/node/24.16.0/lib/node_modules/corepack/shims/nodewin/pnpm
/root/.vite-plus/js_runtime/node/24.16.0/lib/node_modules/corepack/shims/pnpm
/root/.vite-plus/package_manager/pnpm
/root/.vite-plus/package_manager/pnpm/11.3.0/pnpm
/root/.vite-plus/package_manager/pnpm/11.3.0/pnpm/bin/pnpm
/root/.vite-plus/package_manager/pnpm/11.2.2/pnpm
/root/.vite-plus/package_manager/pnpm/11.2.2/pnpm/bin/pnpm

Validations

• Read the Contributing Guidelines.
• Check that there isn't already an issue for the same bug.
• Confirm this is a Vite+ issue and not an upstream issue (Vite, Vitest, tsdown, Rolldown, or Oxc).
• The provided reproduction is a minimal reproducible example.

[fengmk2]

https://github.com/eggplants/michixa/blob/dada49e83965223ca89fe65d5045641ec7cc6128/package.json#L39
Indeed, when packageManager is configured, we should automatically add the corresponding package manager bin to the PATH environment variable.