feat: add standard script aliases

[rajanpanth]

Description

Fixes #303.

Adds a final script-alias pass for generated package.json files:

• start mirrors dev
• test mirrors test:unit when unit tests are present
• test mirrors test:e2e for e2e-only projects
• existing start or test scripts are preserved

This keeps the existing dev, test:unit, and test:e2e commands for compatibility while adding the standard npm script names requested in the issue.

Validation:

• pnpm install --frozen-lockfile --store-dir "D:\grand-final prr\.cache\pnpm-store-create-vue"
• pnpm run build
• pnpm run test:unit
• pnpm run format-check
• pnpm exec vp lint index.ts utils/packageScripts.ts __test__/packageScripts.spec.ts
• git diff --check
• Generated sample projects with the built bundle for default, unit-only, e2e-only, unit+e2e, and Cypress-only combinations, then inspected their scripts output.

Note: the install command used command-scoped COREPACK_HOME, PNPM_HOME, CYPRESS_CACHE_FOLDER, TEMP, and TMP under D:\grand-final prr\.cache because this local machine's C: drive is full. I also attempted pnpm run snapshot after initializing playground, but it failed locally before generating templates with zx's No quote function is defined in this workspace path; the playground submodule was restored afterward and is intentionally not included, per CONTRIBUTING.md.