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)

data/metadata/final_metadata.json

@@ -0,0 +1,49 @@
+{
+  "processed_at": "2026-02-10T16:10:49.295018+00:00",
+  "total_datasets": 7,
+  "total_size_mb": 16.977967262268066,
+  "datasets": {
+    "electricity_prices": {
+      "path": "/home/user/energy-test-data/data/processed/electricity_prices.parquet",
+      "size_mb": 2.2755775451660156,
+      "rows": 72005,
+      "columns": 7
+    },
+    "battery_capacity": {
+      "path": "/home/user/energy-test-data/data/processed/battery_capacity.parquet",
+      "size_mb": 4.204527854919434,
+      "rows": 144010,
+      "columns": 7
+    },
+    "renewable_generation": {
+      "path": "/home/user/energy-test-data/data/processed/renewable_generation.parquet",
+      "size_mb": 4.482715606689453,
+      "rows": 216015,
+      "columns": 7
+    },
+    "conventional_generation": {
+      "path": "/home/user/energy-test-data/data/processed/conventional_generation.parquet",
+      "size_mb": 2.749570846557617,
+      "rows": 144010,
+      "columns": 6
+    },
+    "load_profiles": {
+      "path": "/home/user/energy-test-data/data/processed/load_profiles.parquet",
+      "size_mb": 1.861943244934082,
+      "rows": 72005,
+      "columns": 6
+    },
+    "data_centers": {
+      "path": "/home/user/energy-test-data/data/processed/data_centers.parquet",
+      "size_mb": 1.0422554016113281,
+      "rows": 72005,
+      "columns": 6
+    },
+    "bitcoin_mining": {
+      "path": "/home/user/energy-test-data/data/processed/bitcoin_mining.parquet",
+      "size_mb": 0.3613767623901367,
+      "rows": 14401,
+      "columns": 6
+    }
+  }
+}