Add new daemons and debug scripts for Sigenergy and Oracle functionalities

- Implement `sigen_daemon.py` to poll Sigenergy plant metrics and store snapshots.
- Create `web_daemon.py` for serving a web interface with various endpoints.
- Add debug scripts:
  - `debug_duplicates.py` to find duplicate target times in forecast data.
  - `debug_energy_forecast.py` to print baseline energy forecast curves.
  - `debug_oracle_evaluations.py` to run the oracle evaluator.
  - `debug_sigen.py` to inspect stored Sigenergy plant snapshots.
  - `debug_weather.py` to trace resolved truth data.
  - `modbus_test.py` for exploring Sigenergy plants or inverters over Modbus TCP.
- Introduce `oracle_evaluator.py` for evaluating stored oracle predictions against actuals.
- Add TCN training scripts in `tcn` directory for training usage sequence models.

docs/ingestion-and-storage.md

@@ -200,6 +200,40 @@ Notes:
 - future prediction modules can join this to `weather_forecast_points`
 - make this a hypertable on `resolved_at`
 
+### `sigen_plant_snapshots`
+
+High-resolution Sigenergy plant state from Modbus TCP.
+
+Core fields:
+- `observed_at`
+- `received_at`
+- `source`
+- `solar_power_w`
+- `battery_soc_pct`
+- `battery_soh_pct`
+- `battery_power_w`
+- `grid_power_w`
+- `grid_import_w`
+- `grid_export_w`
+- `load_power_w`
+- `plant_active_power_w`
+- `accumulated_pv_energy_kwh`
+- `daily_consumed_energy_kwh`
+- `accumulated_consumed_energy_kwh`
+- status fields for EMS, running state, and grid sensor state
+- `raw_values`
+
+Notes:
+- raw polling target is `SIGEN_POLL_SECONDS=5`
+- make this a hypertable on `observed_at`
+- keep raw JSON during integration so unsupported or surprising registers can be debugged
+- rollup views should preserve averages, min/max spikes, and sample counts so short-duration usage signatures are not erased completely
+
+Initial rollups:
+- `sigen_plant_snapshots_1m`
+- `sigen_plant_snapshots_15m`
+- `sigen_plant_snapshots_1h`
+
 ### `system_events`
 
 Operational events from collectors, storage, Gibil, and publishers.