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>

tests/Feature/Admin/BacktestResourceTest.php

@@ -0,0 +1,59 @@
+<?php
+
+use App\Filament\Resources\Backtests\BacktestResource;
+use App\Filament\Resources\Backtests\Pages\ListBacktests;
+use App\Filament\Resources\Backtests\Pages\ViewBacktest;
+use App\Models\Backtest;
+use App\Models\User;
+use Illuminate\Foundation\Testing\RefreshDatabase;
+use Livewire\Livewire;
+
+uses(RefreshDatabase::class);
+
+beforeEach(function () {
+    $this->admin = User::factory()->admin()->create();
+    $this->actingAs($this->admin);
+});
+
+it('lists backtests', function () {
+    $backtests = Backtest::factory()->count(3)->create();
+
+    Livewire::test(ListBacktests::class)
+        ->assertOk()
+        ->assertCanSeeTableRecords($backtests);
+});
+
+it('shows the calibration table on the view page', function () {
+    $backtest = Backtest::factory()->create([
+        'calibration_table' => [
+            '0.0-0.5' => 0.55,
+            '0.5-1.0' => 0.65,
+            '1.0+' => 0.72,
+        ],
+    ]);
+
+    Livewire::test(ViewBacktest::class, ['record' => $backtest->id])
+        ->assertOk()
+        ->assertSee('0.0-0.5')
+        ->assertSee('55%')
+        ->assertSee('1.0+')
+        ->assertSee('72%');
+});
+
+it('disables create and edit', function () {
+    $backtest = Backtest::factory()->create();
+
+    expect(BacktestResource::canCreate())->toBeFalse()
+        ->and(BacktestResource::canEdit($backtest))->toBeFalse()
+        ->and(BacktestResource::canDelete($backtest))->toBeFalse();
+});
+
+it('filters backtests below the ship gate', function () {
+    $shippable = Backtest::factory()->create(['directional_accuracy' => 65.00]);
+    $marginal = Backtest::factory()->create(['directional_accuracy' => 58.00]);
+
+    Livewire::test(ListBacktests::class)
+        ->filterTable('below_ship_gate')
+        ->assertCanSeeTableRecords([$marginal])
+        ->assertCanNotSeeTableRecords([$shippable]);
+});