feat: Add MySQL to PostgreSQL migration tool with JSONB transformation

Implement comprehensive migration solution with:
- Full and incremental migration modes
- JSONB schema transformation for RAWDATACOR and ELABDATADISP tables
- Native PostgreSQL partitioning (2014-2031)
- Optimized GIN indexes for JSONB queries
- Rich logging with progress tracking
- Complete benchmark system for MySQL vs PostgreSQL comparison
- CLI interface with multiple commands (setup, migrate, benchmark)
- Configuration management via .env file
- Error handling and retry logic
- Batch processing for performance (configurable batch size)

Database transformations:
- RAWDATACOR: 16 Val columns + units → single JSONB measurements
- ELABDATADISP: 25+ measurement fields → structured JSONB with categories

🤖 Generated with Claude Code

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

.gitignore

@@ -0,0 +1,32 @@
+# Environment variables
+.env
+.env.local
+.env.*.local
+
+# Python-generated files
+__pycache__/
+*.py[oc]
+build/
+dist/
+wheels/
+*.egg-info
+
+# Virtual environments
+.venv
+
+# IDE
+.vscode/
+.idea/
+*.swp
+*.swo
+*~
+.DS_Store
+
+# Testing
+.pytest_cache/
+.coverage
+
+# Project specific
+*.log
+migration_state.json
+benchmark_results/