feat: add --version flag to CLI argument parser

Implement hatch --version command to display application version:

- Add importlib.metadata imports (version, PackageNotFoundError)
- Add get_hatch_version() helper function with error handling
- Add --version argument to main parser using argparse action='version'

The version is retrieved dynamically from package metadata via
importlib.metadata.version('hatch'). Falls back to 'unknown (development mode)'
if package is not installed.

Output format: 'hatch <version>' (e.g., 'hatch 0.6.1')

No short form (-v) to avoid conflict with existing package version flag
in subcommands.

Related to: Phase 1 analysis (version_command_analysis_v1.md)

Author: LittleCoinCoin

hatch/cli_hatch.py

@@ -13,13 +13,28 @@
 import sys
 from pathlib import Path
 from typing import Optional, List
+from importlib.metadata import version, PackageNotFoundError
 
 from hatch.environment_manager import HatchEnvironmentManager
 from hatch_validator import HatchPackageValidator
 from hatch_validator.package.package_service import PackageService
 from hatch.template_generator import create_package_template
 from hatch.mcp_host_config import MCPHostConfigurationManager, MCPHostType, MCPHostRegistry, MCPServerConfig
 
+
+def get_hatch_version() -> str:
+    """Get Hatch version from package metadata.
+
+    Returns:
+        str: Version string from package metadata, or 'unknown (development mode)'
+             if package is not installed.
+    """
+    try:
+        return version('hatch')
+    except PackageNotFoundError:
+        return 'unknown (development mode)'
+
+
 def parse_host_list(host_arg: str):
     """Parse comma-separated host list or 'all'."""
     if not host_arg:
@@ -944,6 +959,14 @@ def main():
 
     # Create argument parser
     parser = argparse.ArgumentParser(description="Hatch package manager CLI")
+
+    # Add version argument
+    parser.add_argument(
+        '--version',
+        action='version',
+        version=f'%(prog)s {get_hatch_version()}'
+    )
+
     subparsers = parser.add_subparsers(dest="command", help="Command to execute")
 
     # Create template command