feat: add generateLlmPredictionWithContext with web search geopolitical context

- New method uses web_search_20260209 server-side tool so Claude fetches
  48h of oil/geopolitical news autonomously before predicting direction
- Prompt uses raw prices only — no pre-computed EWMA indicators
- pause_turn loop handles server-side search continuation (up to 5 iters)
- generatePrediction() now tries context method first, falls back to
  generateLlmPrediction(), then EWMA
- Default model updated to claude-sonnet-4-6

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

app/Services/OilPriceService.php

@@ -104,7 +104,8 @@ class OilPriceService
         $prediction = null;
 
         if (config('services.anthropic.api_key')) {
-            $prediction = $this->generateLlmPrediction($prices);
+            $prediction = $this->generateLlmPredictionWithContext($prices);
+            $prediction ??= $this->generateLlmPrediction($prices);
         }
 
         $prediction ??= $this->generateEwmaPrediction($prices);
@@ -204,6 +205,104 @@ class OilPriceService
         }
     }
 
+    /**
+     * LLM prediction with 48h geopolitical context via Anthropic web search.
+     * Claude searches for recent oil/geopolitical news before answering.
+     * Reasons from raw prices only — no pre-computed indicators in prompt.
+     */
+    public function generateLlmPredictionWithContext(Collection $prices): ?PricePrediction
+    {
+        $priceList = $prices->sortBy('date')
+            ->map(fn (BrentPrice $p) => "{$p->date->toDateString()}: \${$p->price_usd}")
+            ->implode("\n");
+
+        $prompt = <<<PROMPT
+            You are analyzing Brent crude oil price data for a UK fuel price alert service.
+            Your goal is to predict the short-term direction over the next 3–5 days.
+
+            First, search for recent news (last 48 hours) about:
+            - Brent crude oil price movements
+            - OPEC+ production decisions or announcements
+            - Major geopolitical events affecting oil supply (Middle East, Russia, US sanctions)
+            - Global demand signals (China economic data, US inventory reports)
+
+            Then, combining the news context with the price history below, predict the direction.
+
+            Recent Brent crude prices (USD/barrel):
+            {$priceList}
+
+            Respond with JSON only, no other text:
+            {"direction": "rising|falling|flat", "confidence": 0-85, "reasoning": "one sentence combining price trend and key news factor"}
+            PROMPT;
+
+        $url = 'https://api.anthropic.com/v1/messages';
+        $messages = [['role' => 'user', 'content' => $prompt]];
+        $response = null;
+
+        try {
+            for ($i = 0; $i < 5; $i++) {
+                $response = $this->apiLogger->send('anthropic', 'POST', $url, fn () => Http::timeout(30)
+                    ->withHeaders([
+                        'x-api-key' => config('services.anthropic.api_key'),
+                        'anthropic-version' => '2023-06-01',
+                    ])
+                    ->post($url, [
+                        'model' => config('services.anthropic.model', 'claude-sonnet-4-6'),
+                        'max_tokens' => 1024,
+                        'tools' => [['type' => 'web_search_20260209', 'name' => 'web_search']],
+                        'messages' => $messages,
+                    ]));
+
+                if (! $response->successful()) {
+                    Log::error('OilPriceService: Anthropic context request failed', ['status' => $response->status()]);
+
+                    return null;
+                }
+
+                if ($response->json('stop_reason') !== 'pause_turn') {
+                    break;
+                }
+
+                $messages[] = ['role' => 'assistant', 'content' => $response->json('content')];
+            }
+
+            $text = collect($response->json('content') ?? [])
+                ->firstWhere('type', 'text')['text'] ?? '';
+
+            $text = preg_replace('/^```(?:json)?\s*/m', '', trim($text));
+            $text = preg_replace('/```\s*$/m', '', $text);
+            $data = json_decode(trim($text), true);
+
+            if (! isset($data['direction'], $data['confidence'], $data['reasoning'])) {
+                Log::error('OilPriceService: unexpected context LLM response format', ['text' => $text]);
+
+                return null;
+            }
+
+            $direction = TrendDirection::tryFrom($data['direction']);
+            $confidence = min((int) $data['confidence'], self::LLM_MAX_CONFIDENCE);
+
+            if ($direction === null) {
+                Log::error('OilPriceService: invalid direction in context LLM response', ['direction' => $data['direction']]);
+
+                return null;
+            }
+
+            return new PricePrediction([
+                'predicted_for' => now()->toDateString(),
+                'source' => PredictionSource::Llm,
+                'direction' => $direction,
+                'confidence' => $confidence,
+                'reasoning' => $data['reasoning'],
+                'generated_at' => now(),
+            ]);
+        } catch (Throwable $e) {
+            Log::error('OilPriceService: generateLlmPredictionWithContext failed', ['error' => $e->getMessage()]);
+
+            return null;
+        }
+    }
+
     /**
      * Option A — EWMA-based trend extrapolation. Used as fallback when LLM is unavailable.
      * Compares the 3-day EWMA against the 7-day EWMA to detect direction.