refactor: restructure core modules into context and memory packages

- Move pm_init components to dedicated packages
- context/: PM mode initialization and contracts
- memory/: Reflexion memory system
- Remove deprecated superclaude/core/pm_init/

Breaking change: Import paths updated
- Old: superclaude.core.pm_init.context_contract
- New: superclaude.context.contract

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

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

superclaude/context/__init__.py

@@ -0,0 +1,12 @@
+"""Project Context Management
+
+Detects and manages project-specific configuration:
+- Context Contract (project rules)
+- Project structure detection
+- Initialization
+"""
+
+from .contract import ContextContract
+from .init import initialize_context
+
+__all__ = ["ContextContract", "initialize_context"]