fix(ci): repair adapter-test and doc coverage

[Astro-Han]

Description

Fix the two currently failing CI checks without expanding scope.

• point the adapter Vitest project at src/clis/**/*.test.ts and exclude that path from the unit project
• make doc coverage ignore helper-only top-level directories such as clis/slock/_utils.js, while still counting nested-only adapter directories
• add regression tests covering Vitest project discovery and the doc-coverage edge cases

Related issue:

N/A

Type of Change

• 🐛 Bug fix
• ✨ New feature
• 🌐 New site adapter
• 📝 Documentation
• ♻️ Refactor
• 🔧 CI / build / tooling

Checklist

• I ran the checks relevant to this PR
• I updated tests or docs if needed
• I included output or screenshots when useful

Documentation (if adding/modifying an adapter)

• Added doc page under docs/adapters/ (if new adapter)
• Updated docs/adapters/index.md table (if new adapter)
• Updated sidebar in docs/.vitepress/config.mts (if new adapter)
• Updated README.md / README.zh-CN.md when command discoverability changed
• Used positional args for the command's primary subject unless a named flag is clearly better
• Normalized expected adapter failures to CliError subclasses instead of raw Error

Screenshots / Output

$ npx tsc --noEmit
(exit 0)

$ npm test -- --reporter=verbose
49 passed, 585 passed, 2 skipped

$ npm run test:adapter -- --reporter=verbose
1 passed, 3 passed

$ bash scripts/check-doc-coverage.sh --strict
Doc Coverage: 84/84 adapters documented
All adapters have documentation.