feat: implement markitect installer with version/release commands (issue #80)

- Add comprehensive version information system with git integration
- Add `markitect version` and `markitect release` commands with multiple output formats
- Add global `--version` flag for quick version checking
- Create Python installer script with advanced options (install.py)
- Create shell installer wrapper for easy installation (install.sh)
- Add comprehensive installation documentation (INSTALL.md)
- Support user and system-wide installations with virtual environments
- Include development mode installation with test dependencies
- Add installation status checking and uninstall functionality

Commands added:
- `markitect --version` - Quick version display
- `markitect version [--short]` - Detailed version information
- `markitect release [--format text|json|yaml]` - Release information

Installer features:
- Automatic virtual environment creation
- Symbolic link management for global access
- Custom installation paths and prefixes
- Development mode with test dependencies
- Installation validation and troubleshooting

Resolves #80

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-Authored-By: Claude <noreply@anthropic.com>

markitect/cli.py

@@ -27,6 +27,7 @@ import builtins
 
 from .database import DatabaseManager
 from .legacy_compat import LegacyMode, emit_deprecation_warning, legacy_switch_option
+from .__version__ import get_version_info, get_release_info
 
 # Import legacy system components for advanced management
 try:
@@ -175,10 +176,20 @@ def format_output(data, output_format):
         return format_output(data, 'table')
 
 
+def print_version(ctx, param, value):
+    """Callback to print version and exit."""
+    if not value or ctx.resilient_parsing:
+        return
+    version_info = get_version_info()
+    click.echo(version_info['full_version'])
+    ctx.exit()
+
 @click.group()
 @click.option('--verbose', '-v', is_flag=True, help='Enable verbose output')
 @click.option('--config', 'config_file', type=click.Path(exists=True), help='Configuration file path')
 @click.option('--database', type=click.Path(), help='Database file path')
+@click.option('--version', is_flag=True, expose_value=False, is_eager=True,
+              callback=print_version, help='Show version and exit')
 @pass_config
 def cli(config, verbose, database, config_file):
     """
@@ -218,6 +229,63 @@ def cli(config, verbose, database, config_file):
 
 # Issue management commands removed - use dedicated 'issue' CLI or 'tddai' CLI instead
 
+# Version and release information commands
+
+@cli.command()
+@click.option('--short', is_flag=True, help='Show only version number')
+def version(short):
+    """Show MarkiTect version information."""
+    version_info = get_version_info()
+
+    if short:
+        click.echo(version_info['full_version'])
+    else:
+        click.echo("MarkiTect Version Information")
+        click.echo("============================")
+        click.echo(f"Version: {version_info['full_version']}")
+        click.echo(f"Base Version: {version_info['version']}")
+
+        if version_info['is_git_repo']:
+            click.echo(f"Git Commit: {version_info['git_commit'] or 'N/A'}")
+            click.echo(f"Git Branch: {version_info['git_branch'] or 'N/A'}")
+            if version_info['git_tag']:
+                click.echo(f"Git Tag: {version_info['git_tag']}")
+            click.echo(f"Development Build: {'Yes' if version_info['is_development'] else 'No'}")
+        else:
+            click.echo("Git Repository: Not available")
+
+
+@cli.command()
+@click.option('--format', 'output_format', default='text',
+              type=click.Choice(['text', 'json', 'yaml']),
+              help='Output format (text, json, yaml)')
+def release(output_format):
+    """Show MarkiTect release information."""
+    release_info = get_release_info()
+
+    if output_format == 'json':
+        import json
+        click.echo(json.dumps(release_info, indent=2))
+    elif output_format == 'yaml':
+        import yaml
+        click.echo(yaml.dump(release_info, default_flow_style=False))
+    else:
+        # Text format
+        click.echo("MarkiTect Release Information")
+        click.echo("============================")
+        click.echo(f"Version: {release_info['full_version']}")
+        click.echo(f"Release Type: {release_info['release_type']}")
+        click.echo(f"Build From: {release_info['build_from']}")
+        click.echo(f"Commit: {release_info['commit']}")
+        click.echo(f"Clean Build: {'Yes' if release_info['clean_build'] else 'No'}")
+
+        if release_info['is_git_repo']:
+            click.echo(f"Git Repository: Available")
+            if release_info['git_tag']:
+                click.echo(f"Tagged Release: {release_info['git_tag']}")
+        else:
+            click.echo("Git Repository: Not available")
+
 
 @cli.command()
 @click.argument('file_path', type=click.Path(exists=True))