fix: pass $emit into synthesiseBvj so dbn-legal-agent keepalives fire

includes/BvjAnalyzerAgent.php

@@ -359,7 +359,8 @@ final class DbnBvjAnalyzerAgent
         $synthesis = $this->synthesiseBvj(
             $docText, $docMeta, $parties, $timelineEvents,
             $subQuestions, $numberedSources,
-            $advocateRole, $engine, $language, $controls['temperature'], $additionalNotes
+            $advocateRole, $engine, $language, $controls['temperature'], $additionalNotes,
+            $emit
         );
         $this->stepTimings['synthesis'] = $this->elapsedMs($stepStart);
         $emitStep('synthesis', 'Synthesis',
@@ -695,7 +696,8 @@ PROMPT;
         string    $engine,
         string    $language,
         float     $temperature,
-        string $additionalNotes
+        string    $additionalNotes,
+        ?callable $emit = null
     ): array {
         $locale   = $language === 'no' ? 'Norwegian' : 'English';
         $roleStr  = $advocateRole !== '' ? $advocateRole : 'the affected party';