fix: skip thinking parts in Gemini vision response + extract JSON from any position

gemini-3.x models return thinking blocks with thought:true flag in parts[].
Filter those out so only actual response text is used.
Also extract the first {...} JSON object from the text so stray content
before or after (like '040825') doesn't break parsing.

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

app/Services/GeminiVisionService.php

@@ -77,9 +77,12 @@ class GeminiVisionService
         $inputTokens  = $response->json('usageMetadata.promptTokenCount', 0);
         $outputTokens = $response->json('usageMetadata.candidatesTokenCount', 0);
 
-        // Collect text from ALL parts (newer models may put JSON in parts[1] if thinking is in parts[0])
+        // Skip thought parts (gemini-3.x thinking blocks), only keep actual response text
         $parts = $response->json('candidates.0.content.parts', []);
-        $text  = implode("\n", array_column(array_filter($parts, fn($p) => isset($p['text'])), 'text'));
+        $text  = implode("\n", array_column(
+            array_filter($parts, fn($p) => isset($p['text']) && empty($p['thought'])),
+            'text'
+        ));
 
         Log::info('[Gemini Vision] raw response: ' . substr($text, 0, 500));
 
@@ -129,7 +132,13 @@ PROMPT;
 
     private function parseRespuesta(string $text): ?array
     {
-        $text = trim(preg_replace('/```json\s*|\s*```/', '', $text));
+        // Strip markdown fences
+        $text = preg_replace('/```json\s*|\s*```/', '', $text);
+        // Extract the first JSON object found anywhere in the text
+        if (preg_match('/\{.*\}/s', $text, $m)) {
+            $text = $m[0];
+        }
+        $text = trim($text);
         $json = json_decode($text, true);
 
         if (! is_array($json) || isset($json['error'])) {