refactor: Major reorganization of optimization_engine module structure

BREAKING CHANGE: Module paths have been reorganized for better maintainability.
Backwards compatibility aliases with deprecation warnings are provided.

New Structure:
- core/           - Optimization runners (runner, intelligent_optimizer, etc.)
- processors/     - Data processing
  - surrogates/   - Neural network surrogates
- nx/             - NX/Nastran integration (solver, updater, session_manager)
- study/          - Study management (creator, wizard, state, reset)
- reporting/      - Reports and analysis (visualizer, report_generator)
- config/         - Configuration management (manager, builder)
- utils/          - Utilities (logger, auto_doc, etc.)
- future/         - Research/experimental code

Migration:
- ~200 import changes across 125 files
- All __init__.py files use lazy loading to avoid circular imports
- Backwards compatibility layer supports old import paths with warnings
- All existing functionality preserved

To migrate existing code:
  OLD: from optimization_engine.nx_solver import NXSolver
  NEW: from optimization_engine.nx.solver import NXSolver

  OLD: from optimization_engine.runner import OptimizationRunner
  NEW: from optimization_engine.core.runner import OptimizationRunner

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

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

optimization_engine/study/__init__.py

@@ -0,0 +1,60 @@
+"""
+Study Management
+================
+
+Study creation, state management, and lifecycle.
+
+Modules:
+- creator: Study creation from templates
+- wizard: Interactive study setup wizard
+- state: Study state tracking
+- reset: Study reset functionality
+- continuation: Resume interrupted studies
+"""
+
+# Lazy imports to avoid circular dependencies
+def __getattr__(name):
+    if name == 'StudyCreator':
+        from .creator import StudyCreator
+        return StudyCreator
+    elif name == 'create_study':
+        from .creator import create_study
+        return create_study
+    elif name == 'StudyWizard':
+        from .wizard import StudyWizard
+        return StudyWizard
+    elif name == 'StudyState':
+        from .state import StudyState
+        return StudyState
+    elif name == 'StudyReset':
+        from .reset import StudyReset
+        return StudyReset
+    elif name == 'reset_study':
+        from .reset import reset_study
+        return reset_study
+    elif name == 'StudyContinuation':
+        from .continuation import StudyContinuation
+        return StudyContinuation
+    elif name == 'continue_study':
+        from .continuation import continue_study
+        return continue_study
+    elif name == 'BenchmarkingSubstudy':
+        from .benchmarking import BenchmarkingSubstudy
+        return BenchmarkingSubstudy
+    elif name == 'generate_history':
+        from .history_generator import generate_history
+        return generate_history
+    raise AttributeError(f"module 'optimization_engine.study' has no attribute '{name}'")
+
+__all__ = [
+    'StudyCreator',
+    'create_study',
+    'StudyWizard',
+    'StudyState',
+    'StudyReset',
+    'reset_study',
+    'StudyContinuation',
+    'continue_study',
+    'BenchmarkingSubstudy',
+    'generate_history',
+]