refactor: migrated package manager to pnpm

[mfranzke]

Proposed changes

Migrated node package manager from npm to pnpm.

Types of changes

• Bugfix (non-breaking change that fixes an issue)
• New feature (non-breaking change which adds functionality)
• Refactoring (improvements to existing components or architectural decisions)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• Documentation Update (if none of the other choices apply)

Further comments

[github-actions]

🔭🐙🐈 Test this branch here: https://db-ux-design-system.github.io/core-web/review/refactor-migrated-package-manager-to-pnpm

[Copilot]

Pull Request Overview

This PR migrates the project's package manager from npm to pnpm across the entire monorepo. This is a comprehensive refactoring that updates all package.json scripts, workflow files, documentation, and configuration files to use pnpm commands instead of npm.

Key changes include:

• Replaced npm workspace commands with pnpm filter syntax
• Updated npm-run-all usage with pnpm's built-in parallel execution and regex patterns
• Modified CI/CD workflows and GitHub Actions to use pnpm
• Added pnpm workspace configuration and package manager specification

Reviewed Changes

Copilot reviewed 70 out of 72 changed files in this pull request and generated 1 comment.

Show a summary per file

File	Description
pnpm-workspace.yaml	New pnpm workspace configuration file defining package locations
package.json	Updated package manager field and removed npm workspaces config, added pnpm overrides
scripts/package.json	Converted all npm workspace commands to pnpm filter syntax
showcases/*/package.json	Updated npm-run-all patterns to pnpm regex patterns and npx to pnpm exec
.github/workflows/*.yml	Updated all CI/CD workflows to use pnpm commands instead of npm
packages/*/package.json	Converted build scripts from npm-run-all to pnpm regex patterns
docs/*.md	Updated documentation examples to use pnpm exec instead of npx

Comments suppressed due to low confidence (1)

package.json:145

• Missing closing brace for the 'pnpm' configuration object. The 'overrides' property should be nested within the 'pnpm' object, not at the root level.

    }

[Copilot]

The regex pattern '/^build:[^:]$/' may not work as expected. Consider using 'build:' or testing this pattern thoroughly, as pnpm's regex support for script patterns might differ from npm-run-all.

Suggested change

	"build": "pnpm run '/^build:[^:]*$/'",
	"build": "pnpm run build:*",