Add local setup helper script

[pappensex]

Summary

• add a setup-local script to prepare environment files and install dependencies
• document the helper in README and scripts/README for quicker onboarding
• expose npm run setup:local alias for consistent usage

Testing

• Not run (not requested)

---

Codex Task

[vercel]

Deployment failed with the following error:

The `vercel.json` schema validation failed with the following message: should NOT have additional property `output`

Learn More: https://vercel.com/docs/concepts/projects/project-configuration

[vercel]

The latest updates on your projects. Learn more about Vercel for GitHub.

Project	Deployment	Preview	Comments	Updated (UTC)
transzendenz	Error			Nov 20, 2025 3:36am
yoni-app	Error			Nov 20, 2025 3:36am

[Copilot]

Pull Request Overview

This PR adds a local development setup helper script to streamline the onboarding process for new developers. The script automates environment preparation and dependency installation.

• Adds setup-local.sh script that checks prerequisites, copies environment files, and installs dependencies
• Documents the new script in both scripts/README.md and the main README.md
• Exposes npm run setup:local command for convenient access

Reviewed Changes

Copilot reviewed 4 out of 4 changed files in this pull request and generated no comments.

File	Description
scripts/setup-local.sh	New bash script that verifies Node.js/npm, creates .env.local from .env.example, and runs npm install
scripts/README.md	Adds documentation for the new setup script under "Local Development" section
package.json	Adds setup:local npm script alias for running the setup script
README.md	Updates "Lokale Entwicklung" section to recommend the setup script as the quick start method

---

💡 Add Copilot custom instructions for smarter, more guided reviews. Learn how to get started.