describe-changes@v1: with concatenate mode: append

✨ PR Description

Purpose: Update build and release configuration to standardize on "hello-theme" naming convention in scripts and workflows.

Main changes:

• Replaced dynamic name derivation with hardcoded "hello-theme" prefix for build artifacts
• Updated path references in build scripts to use consistent naming pattern
• Upgraded create-pull-request action from v5 to v6 with enhanced PR description template
• Fixed sed pattern in version update script with proper closing parenthesis

Generated by LinearB AI and added by gitStream.
_{AI-generated content may contain inaccuracies. Please verify before using. We'd love your feedback! 🚀}