feat: implement modular capability system with automatic discovery

- Move release management to capabilities/release-management/ with complete Makefile
- Create automatic capability discovery system in scripts/capability_discovery.mk
- Add capability-manager subagent for managing modular architecture
- Implement target delegation system enabling capability-name-target patterns
- Create Makefiles for markitect-content, markitect-utils, and issue-facade capabilities
- Remove legacy release management code and documentation from main project
- Update main Makefile to use capability discovery and delegation
- Add comprehensive capability status, help, and management targets

The capability system provides:
- Automatic discovery of capabilities with Makefiles
- Clean target delegation without conflicts
- Modular architecture following established patterns
- Comprehensive help and status reporting
- Zero-conflict capability integration

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

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

capabilities/release-management/src/release_management/registries/__init__.py

@@ -0,0 +1,23 @@
+"""
+Package registry implementations.
+
+This module provides registry clients for publishing packages to various platforms:
+- Gitea package registries
+- PyPI and Test PyPI
+- Extensible factory for custom registries
+"""
+
+from .factory import RegistryFactory
+from .base import RegistryInterface, RegistryConfig
+from .gitea.registry import GiteaRegistry
+from .gitea.config import GiteaConfig
+from .gitea.exceptions import GiteaError
+
+__all__ = [
+    "RegistryFactory",
+    "RegistryInterface",
+    "RegistryConfig",
+    "GiteaRegistry",
+    "GiteaConfig",
+    "GiteaError",
+]