feat(admin): add Filament resources for the forecasting stack

Adds three resources under a new "Forecasting" navigation group: a full-CRUD
WatchedEventResource for the Layer 5 volatility detector, plus read-only
WeeklyForecastResource and BacktestResource so the ridge model output and
its calibration can be inspected without SQL.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

app/Filament/Resources/WatchedEvents/Pages/CreateWatchedEvent.php

@@ -0,0 +1,11 @@
+<?php
+
+namespace App\Filament\Resources\WatchedEvents\Pages;
+
+use App\Filament\Resources\WatchedEvents\WatchedEventResource;
+use Filament\Resources\Pages\CreateRecord;
+
+class CreateWatchedEvent extends CreateRecord
+{
+    protected static string $resource = WatchedEventResource::class;
+}