Initial commit: Energy test data generation pipeline

Add complete test data preparation system for energy trading strategy
demo. Includes configuration, data generation scripts, and validation
tools for 7 datasets covering electricity prices, battery capacity,
renewable/conventional generation, load profiles, data centers, and
mining data.

Excluded from git: Actual parquet data files (data/raw/, data/processed/)
can be regenerated using the provided scripts.

Datasets:
- electricity_prices: Day-ahead and real-time prices (5 regions)
- battery_capacity: Storage system charge/discharge cycles
- renewable_generation: Solar, wind, hydro with forecast errors
- conventional_generation: Gas, coal, nuclear plant outputs
- load_profiles: Regional demand with weather correlations
- data_centers: Power demand profiles including mining operations
- mining_data: Hashrate, price, profitability (mempool.space API)

.gitignore

@@ -0,0 +1,46 @@
+# Data files - exclude from git
+data/raw/*.parquet
+data/processed/*.parquet
+
+# Python artifacts
+__pycache__/
+test/__pycache__/
+*.py[cod]
+*$py.class
+*.so
+.Python
+build/
+develop-eggs/
+dist/
+downloads/
+eggs/
+.eggs/
+lib/
+lib64/
+parts/
+sdist/
+var/
+wheels/
+*.egg-info/
+.installed.cfg
+*.egg
+
+# Virtual environments
+venv/
+ENV/
+env/
+.venv/
+
+# IDE
+.vscode/
+.idea/
+*.swp
+*.swo
+*~
+
+# OS
+.DS_Store
+Thumbs.db
+
+# Logs
+*.log