refactor(cli): convert main() to Click command group

[michaelos443]

Summary

Converts the free-standing main() coroutine into a proper Click command group to enable adding sub-commands (like deepcode config or deepcode clean) without touching the main logic.

Changes

• Convert main() to Click group: Using @click.group(invoke_without_command=True) decorator
• Add run sub-command: Explicit command for starting the interactive session
• Backwards compatible: Invoking without a sub-command still starts the interactive session
• Security improvement: Replace shell-based __pycache__ cleanup (find/powershell) with secure shutil.rmtree approach
• Add dependency: click>=8.0.0 added to requirements.txt

Usage

# Start interactive session (backwards compatible)
python -m cli.cli_app

# Or explicitly with sub-command
python -m cli.cli_app run

# View available commands
python -m cli.cli_app --help

Adding new sub-commands

New sub-commands can be added easily:

@main.command("config")
def config_cmd() -> None:
    """Manage DeepCode configuration."""
    # config logic here

@main.command("clean")
def clean_cmd() -> None:
    """Clean up generated files and caches."""
    # clean logic here

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Pull Request opened by Augment Code with guidance from the PR author