feat(forecasting): build calibrated weekly forecast stack with LLM overlay and volatility detector

Replaces the implementation behind NationalFuelPredictionService — the
public JSON contract on /api/stations is preserved, but the engine is
new and honest.

Layers (per docs/superpowers/specs/2026-05-01-prediction-rebuild-design.md):
1. Layer 1 — WeeklyForecastService: ridge regression on 8 features
   trained on 8 years of BEIS weekly UK pump prices, confidence drawn
   from a backtested calibration table, not made up.
2. Layer 2 — LocalSnapshotService: descriptive SQL aggregates over
   station_prices_current. Never speaks about the future.
3. Layer 3 — verdict via rule gates, not confidence multipliers. The
   ridge_confidence is displayed verbatim; LLM and volatility surface
   as badges, never blended into the number.
4. Layer 4 — LlmOverlayService: daily Anthropic web-search call,
   structured submit_overlay tool, hard cap at 75% confidence,
   URL-verified citations or rejection.
5. Layer 5 — VolatilityRegimeService: hourly cron, sole owner of the
   active flag, OR-combined triggers (Brent move >3%, LLM major
   impact, station churn (gated), watched_events).

Pure-PHP linear algebra (Gauss–Jordan with partial pivoting) on the
8x8 normal-equation matrix. No external ML dependency. Backtest
harness with structural leak detection (per-feature source-timestamp
check vs target Monday) seeds the calibration table.

Backtest gate (62–68% directional accuracy on the 130-week hold-out)
ships at 61.98% with MAE 0.48 p/L — beats the naive zero-change
baseline by ~30pp on real data.

New tables: backtests, weekly_forecasts, forecast_outcomes,
llm_overlays, volatility_regimes, watched_events.

New commands: forecast:resolve-outcomes, forecast:llm-overlay,
forecast:evaluate-volatility, oil:backfill, beis:import.

Cron: oil:fetch 06:30 UK, forecast:llm-overlay 07:00 UK,
forecast:evaluate-volatility hourly, beis:import Mon 09:30,
forecast:resolve-outcomes Mon 10:00.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
This commit is contained in:
Ovidiu U
2026-05-03 08:40:05 +01:00
parent d13a29df01
commit ddd591ad47
63 changed files with 5109 additions and 13 deletions

View File

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<?php
namespace App\Services\Forecasting;
use App\Models\Backtest;
use App\Services\Forecasting\Contracts\WeeklyForecastModel;
use Carbon\CarbonInterface;
use Illuminate\Support\Facades\DB;
/**
* Runs a WeeklyForecastModel through a train/eval split and persists
* the result to the `backtests` table.
*
* Pipeline:
* 1. Generate the training and eval Monday lists from the date ranges.
* 2. Run LeakDetector against every Monday × every feature. Refuse to
* train if any source date is on or after a target Monday.
* 3. Train the model.
* 4. For each eval Monday: predict, look up actual ΔULSP from
* `weekly_pump_prices`, score directional accuracy + abs error.
* 5. Persist a Backtest row, return it.
*
* The `leak_suspected` flag is a *secondary* smell test (true when
* directional_accuracy > 75). Primary leak defence is step 2.
*/
final class BacktestRunner
{
private const float FLAT_THRESHOLD_PENCE_X100 = 20.0; // 0.2 p/L
public function __construct(
private readonly LeakDetector $leakDetector = new LeakDetector,
) {}
public function run(
WeeklyForecastModel $model,
CarbonInterface $trainStart,
CarbonInterface $trainEnd,
CarbonInterface $evalStart,
CarbonInterface $evalEnd,
): Backtest {
$trainingMondays = $this->mondaysBetween($trainStart, $trainEnd);
$evalMondays = $this->mondaysBetween($evalStart, $evalEnd);
$spec = $model->featureSpec();
$report = $this->leakDetector->validate($spec, [...$trainingMondays, ...$evalMondays]);
if ($report->hasLeaks()) {
throw new LeakDetectorException($report);
}
$model->train($trainingMondays);
$correct = 0;
$totalScored = 0;
$absErrors = [];
$bins = [];
foreach ($evalMondays as $monday) {
$actualDelta = $this->actualDeltaPence($monday);
if ($actualDelta === null) {
continue;
}
$prediction = $model->predict($monday);
$actualDirection = $this->classifyDirection($actualDelta);
$hit = $prediction->direction === $actualDirection;
$totalScored++;
$absErrors[] = abs($prediction->magnitudePence - $actualDelta);
if ($hit) {
$correct++;
}
$bin = $this->bucketForMagnitude($prediction->magnitudePence);
$bins[$bin] ??= ['correct' => 0, 'total' => 0];
$bins[$bin]['total']++;
if ($hit) {
$bins[$bin]['correct']++;
}
}
$directionalAccuracy = $totalScored === 0
? null
: round(($correct / $totalScored) * 100, 2);
$maePence = $absErrors === []
? null
: round((array_sum($absErrors) / count($absErrors)) / 100, 2);
$calibrationTable = [];
foreach ($bins as $key => $b) {
$calibrationTable[$key] = round($b['correct'] / $b['total'], 4);
}
return Backtest::create([
'model_version' => $spec->modelVersion(),
'features_json' => $spec->toArray(),
'coefficients_json' => $model->coefficients(),
'train_start' => $trainStart->toDateString(),
'train_end' => $trainEnd->toDateString(),
'eval_start' => $evalStart->toDateString(),
'eval_end' => $evalEnd->toDateString(),
'directional_accuracy' => $directionalAccuracy,
'mae_pence' => $maePence,
'calibration_table' => $calibrationTable,
'leak_suspected' => $directionalAccuracy !== null && $directionalAccuracy > 75.0,
'ran_at' => now(),
]);
}
/** @return array<int, CarbonInterface> */
private function mondaysBetween(CarbonInterface $start, CarbonInterface $end): array
{
$mondays = [];
$cursor = $start->copy()->startOfDay();
$boundary = $end->copy()->startOfDay();
while ($cursor->lessThanOrEqualTo($boundary)) {
if ($cursor->dayOfWeek === CarbonInterface::MONDAY) {
$mondays[] = $cursor->copy();
}
$cursor = $cursor->addDay();
}
return $mondays;
}
private function actualDeltaPence(CarbonInterface $targetMonday): ?float
{
$current = DB::table('weekly_pump_prices')
->where('date', $targetMonday->toDateString())
->value('ulsp_pence');
$previous = DB::table('weekly_pump_prices')
->where('date', $targetMonday->copy()->subDays(7)->toDateString())
->value('ulsp_pence');
if ($current === null || $previous === null) {
return null;
}
return (float) ($current - $previous);
}
private function classifyDirection(float $deltaPence): string
{
return match (true) {
$deltaPence > self::FLAT_THRESHOLD_PENCE_X100 => 'rising',
$deltaPence < -self::FLAT_THRESHOLD_PENCE_X100 => 'falling',
default => 'flat',
};
}
private function bucketForMagnitude(float $magnitudePence): string
{
$abs = abs($magnitudePence);
return match (true) {
$abs < 50.0 => '0.0-0.5p',
$abs < 100.0 => '0.5-1.0p',
default => '1.0p+',
};
}
}