feat: add postcode resolution to /api/stations and Filament SearchResource

Extends NearbyStationsRequest to accept `postcode` (full or outcode) as an alternative to lat/lng. PostcodeService resolves it via postcodes.io and falls through to coordinates. Also adds SearchResource to the Filament admin panel for viewing logged search activity with fuel type filter and price/distance stats columns. Includes SQLite GREATEST/LEAST function polyfills in AppServiceProvider for test compatibility.

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

app/Services/OilPriceService.php

@@ -86,8 +86,9 @@ class OilPriceService
     }
 
     /**
-     * Generate a prediction using LLM first, falling back to EWMA.
-     * Stores the result in price_predictions and returns it.
+     * Generate predictions from all available sources and store each one.
+     * EWMA always runs. LLM runs when an API key is configured.
+     * Returns the highest-confidence prediction (LLM preferred over EWMA).
      */
     public function generatePrediction(): ?PricePrediction
     {
@@ -101,20 +102,24 @@ class OilPriceService
             return null;
         }
 
-        $prediction = null;
+        $ewma = $this->generateEwmaPrediction($prices);
+
+        if ($ewma !== null) {
+            PricePrediction::create($ewma->toArray());
+        }
+
+        $llm = null;
 
         if (config('services.anthropic.api_key')) {
-            $prediction = $this->generateLlmPredictionWithContext($prices);
-            $prediction ??= $this->generateLlmPrediction($prices);
+            $llm = $this->generateLlmPredictionWithContext($prices);
+            $llm ??= $this->generateLlmPrediction($prices);
+
+            if ($llm !== null) {
+                PricePrediction::create($llm->toArray());personal_access_tokens
+            }
         }
 
-        $prediction ??= $this->generateEwmaPrediction($prices);
-
-        if ($prediction !== null) {
-            PricePrediction::create($prediction->toArray());
-        }
-
-        return $prediction;
+        return $llm ?? $ewma;
     }
 
     /**
@@ -171,9 +176,7 @@ class OilPriceService
             }
 
             $text = $response->json('content.0.text') ?? '';
-            $text = preg_replace('/^```(?:json)?\s*/m', '', trim($text));
-            $text = preg_replace('/```\s*$/m', '', $text);
-            $data = json_decode(trim($text), true);
+            $data = $this->extractJson($text);
 
             if (! isset($data['direction'], $data['confidence'], $data['reasoning'])) {
                 Log::error('OilPriceService: unexpected LLM response format', ['text' => $text]);
@@ -237,10 +240,9 @@ class OilPriceService
 
         $url = 'https://api.anthropic.com/v1/messages';
         $messages = [['role' => 'user', 'content' => $prompt]];
-        $response = null;
 
         try {
-            for ($i = 0; $i < 5; $i++) {
+            for ($i = 0, $response = null; $i < 5; $i++) {
                 $response = $this->apiLogger->send('anthropic', 'POST', $url, fn () => Http::timeout(30)
                     ->withHeaders([
                         'x-api-key' => config('services.anthropic.api_key'),
@@ -249,12 +251,15 @@ class OilPriceService
                     ->post($url, [
                         'model' => config('services.anthropic.model', 'claude-sonnet-4-6'),
                         'max_tokens' => 1024,
-                        'tools' => [['type' => 'web_search_20260209', 'name' => 'web_search']],
+                        'tools' => [['type' => 'web_search_20250305', 'name' => 'web_search']],
                         'messages' => $messages,
                     ]));
 
                 if (! $response->successful()) {
-                    Log::error('OilPriceService: Anthropic context request failed', ['status' => $response->status()]);
+                    Log::error('OilPriceService: Anthropic context request failed', [
+                        'status' => $response->status(),
+                        'body' => $response->body(),
+                    ]);
 
                     return null;
                 }
@@ -266,12 +271,13 @@ class OilPriceService
                 $messages[] = ['role' => 'assistant', 'content' => $response->json('content')];
             }
 
-            $text = collect($response->json('content') ?? [])
-                ->firstWhere('type', 'text')['text'] ?? '';
+            $content = $response->json('content') ?? [];
 
-            $text = preg_replace('/^```(?:json)?\s*/m', '', trim($text));
-            $text = preg_replace('/```\s*$/m', '', $text);
-            $data = json_decode(trim($text), true);
+            $text = collect($content)
+                ->filter(fn ($b) => ($b['type'] ?? '') === 'text')
+                ->implode('text', '');
+
+            $data = $this->extractJson($text);
 
             if (! isset($data['direction'], $data['confidence'], $data['reasoning'])) {
                 Log::error('OilPriceService: unexpected context LLM response format', ['text' => $text]);
@@ -366,6 +372,23 @@ class OilPriceService
         return round($ema, 4);
     }
 
+    /**
+     * Strip markdown code fences from a string and extract the first JSON object found.
+     * Handles prose preambles that Claude sometimes adds before the JSON.
+     */
+    private function extractJson(string $text): ?array
+    {
+        $text = preg_replace('/^```(?:json)?\s*/m', '', trim($text));
+        $text = preg_replace('/```\s*$/m', '', $text);
+        $start = strpos($text, '{');
+        $end = strrpos($text, '}');
+        if ($start === false || $end === false) {
+            return null;
+        }
+
+        return json_decode(substr($text, $start, $end - $start + 1), true) ?: null;
+    }
+
     /**
      * Map a % change magnitude to a 0–EWMA_MAX_CONFIDENCE confidence score.
      * 1.5% → ~30, 3% → ~50, 5%+ → 65.