feat: Excel to SQL Server migration tool for production execution cards

Migrates pressure gauge (PG) and thermometer (TM) data from .xlsm files
into SQL Server executionCard schema, one table per year (PG_2022-2026,
TM_2022-2026). Supports single/multi-table migration, column remapping,
type inference, and dry-run mode via config.yaml.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

.gitignore

@@ -0,0 +1,33 @@
+# Virtual environment
+.venv/
+
+# Python
+__pycache__/
+*.py[cod]
+*$py.class
+*.egg-info/
+dist/
+build/
+
+# IDE
+.vscode/
+.idea/
+*.swp
+*.swo
+
+# OS
+Thumbs.db
+Desktop.ini
+.DS_Store
+
+# Logs
+*.log
+
+# Environment variables / secrets
+.env
+.env.*
+config.yaml
+
+# Excel temp files
+Excel/
+*.tmp