Update README and contributing docs for current setup and validation flow

[Copilot]

The documentation needed to reflect the current Node/npm requirements, streamlined install/build steps, and the required shared-type build step for server compilation.

• Prerequisites & install

  • Specify Node.js 20/npm 10.
  • Use npm run install:all as the single install entrypoint.

• Build & validation

  • Document the required npx tsc --build src/types before server builds.
  • Keep npm run build:all and add a concise validation checklist (types build, full build, lint, backend health check, frontend navigation + Ctrl+/ shortcut).

• Environment variables

  • Clarify Vite usage: rely on import.meta.env (e.g., import.meta.env.VITE_API_URL).

• Contributing

  • Align contributing guide with Node.js 20/npm 10 and the shared-types build step.

Example snippet:

# Required types build
npx tsc --build src/types

# Full build
npm run build:all

# Manual smoke checks
npm run dev:server  # curl http://localhost:3001/health
npm run dev:frontend  # navigate UI, press Ctrl+/

Original prompt

update documentation and readme

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[Copilot]

Pull request overview

This PR updates the README and CONTRIBUTING documentation to reflect the current Node.js requirements, streamlined installation process, and mandatory build order for the Master Prompt Editor monorepo. The changes clarify prerequisites (Node.js 20.x/npm 10.x), consolidate installation to a single command (npm run install:all), document the required shared types build step before server compilation, explain Vite-specific environment variable usage, and add a comprehensive validation checklist for manual smoke testing.

Key Changes

• Updated prerequisites to specify Node.js 20.x and npm 10.x (matching CI requirements)
• Streamlined installation from multiple commands to single npm run install:all command
• Added critical documentation for npx tsc --build src/types requirement before server builds
• Introduced new "Environment Variables" and "Validation Checklist" sections in README
• Aligned CONTRIBUTING.md with README build requirements

Reviewed changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated no comments.

File	Description
README.md	Updated prerequisites (Node.js 20.x/npm 10.x), consolidated installation steps, added environment variables section explaining Vite's import.meta.env, documented required shared types build step, and added comprehensive validation checklist with backend health check and frontend navigation smoke tests
CONTRIBUTING.md	Added Node.js 20.x requirement and referenced shared types build step to align with README and CI configuration