feat: migrate project from cookiecutter to copier template

[paul58914080]

Checklist:

• My code follows the contribution guidelines of this project
• I have performed a self-review of my own code
• My changes generate no new warnings
• I have added tests that prove my fix is effective or that my feature works
• New and existing unit tests pass locally with my changes
• My commits follow conventional commit message guidelines

[Copilot]

Pull Request Overview

This PR migrates the template generation system from Cookiecutter to Copier, modernizing the project's templating approach while maintaining the same hexagonal architecture structure.

Key changes:

• Migration from Cookiecutter to Copier templating syntax (replacing {{cookiecutter.*}} with simpler {{*}} syntax)
• Updated template generation scripts and CI/CD workflows to use Copier instead of Cookiecutter
• Transitioned template file structure to use .jinja extensions and Copier-compatible variable syntax

Reviewed Changes

Copilot reviewed 62 out of 74 changed files in this pull request and generated 1 comment.

Show a summary per file

File	Description
copier.yml	New Copier configuration file defining template variables and defaults
cookiecutter.json	Removed legacy Cookiecutter configuration
generate-copier-template-from-example-project.sh	New script for generating Copier templates, replacing Cookiecutter version
{{app_name}}/**/*.jinja	All template files migrated to Copier syntax with .jinja extensions
.github/workflows/*.yaml	Updated CI workflows to use Copier commands instead of Cookiecutter
README.md	Documentation updated to reflect Copier usage and installation
test-config.yml	Removed Cookiecutter test configuration file
rename_dir.sh	New utility script for directory renaming during migration