Add Auth0 CLI management file for SDD

[Copilot]

This PR adds support for managing the Auth0 CLI through the SDD framework, addressing issue requirements to create an SDD management file for the Auth0 CLI.

Changes Made

• Added lib/sdd/apps/user/auth0: Complete management file implementing:

  • sdd_install() - Downloads and installs Auth0 CLI from GitHub releases
  • sdd_uninstall() - Clean removal of binary and completions
  • sdd_fetch_latest_version() - Retrieves latest version from GitHub API

• Added test/apps/auth0.bats: Test suite covering installation, version verification, completion setup, and uninstall functionality

Implementation Details

The implementation follows the established SDD pattern similar to other CLI tools like xan and circleci:

• Downloads the Linux x86_64 binary from https://github.com/auth0/auth0-cli/releases
• Extracts and installs to $SDD_INSTALL_PREFIX/bin/auth0
• Automatically installs bash completions using the CLI's built-in auth0 completion bash command
• Provides clean uninstall that removes both binary and completion files

Manual Testing

The implementation has been manually verified to:

• ✅ Successfully install Auth0 CLI v1.20.0
• ✅ Generate and install bash completions correctly
• ✅ Execute auth0 --version and other commands properly
• ✅ Cleanly uninstall all components
• ✅ Appear in sdd list -a available applications

Users can now manage their Auth0 CLI installation using standard SDD commands:

sdd install auth0
sdd uninstall auth0

Fixes #20

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