feat: complete Issue #146 final integration testing

Fixed all remaining test failures in test_issue_146_final_integration.py
achieving 100% test success rate (9/9 tests passing):

- Fixed performance monitoring metrics access patterns
- Resolved AssetManager constructor parameter handling
- Implemented missing CLI command methods (add_asset, list_assets, get_asset_info)
- Added cross-platform symlink creation method aliases
- Fixed asset deduplication content uniqueness issues
- Resolved production deployment asset removal workflows
- Fixed performance benchmark dict/hash type conflicts

The asset management system is now production-ready with comprehensive
integration test coverage validating all major workflows and edge cases.

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

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

markitect/assets/registry.py

@@ -210,6 +210,22 @@ class AssetRegistry:
 
             return self._data["assets"][content_hash].copy()
 
+    def get_asset_as_object(self, content_hash: str) -> Optional['Asset']:
+        """Get asset as Asset object by content hash.
+
+        Args:
+            content_hash: SHA-256 hash of the asset content.
+
+        Returns:
+            Asset object or None if not found.
+        """
+        try:
+            asset_dict = self.get_asset(content_hash)
+            from .models import Asset
+            return Asset.from_dict(asset_dict)
+        except RegistryError:
+            return None
+
     def asset_exists(self, content_hash: str) -> bool:
         """Check if asset exists in registry by hash.