#375: preserve whole-number floats in Avro generic wrapper

Add JSON_PRESERVE_ZERO_FRACTION to json_encode in encodeWrapped().
3.0 now stays 3.0 (float) instead of narrowing to 3 (int).

Parity suite updated: three_point_zero assertions now verify
float type preservation end-to-end.

Author: durable-workflow-ops

src/Serializers/Avro.php

@@ -202,7 +202,7 @@ private static function encodeWrapped(mixed $data): string
             // Prefix: 0x00 = generic wrapper mode
             $io->write("\x00");
             $writer->write([
-                'json' => json_encode($data, JSON_THROW_ON_ERROR | JSON_UNESCAPED_SLASHES | JSON_UNESCAPED_UNICODE),
+                'json' => json_encode($data, JSON_THROW_ON_ERROR | JSON_UNESCAPED_SLASHES | JSON_UNESCAPED_UNICODE | JSON_PRESERVE_ZERO_FRACTION),
                 'version' => 1,
             ], $encoder);
 

tests/Feature/V2/V2AvroParitySuiteTest.php

@@ -73,13 +73,13 @@ public function testFloatIntFidelityThroughFullWorkflowLifecycle(): void
         $this->assertIsFloat($output['input_amount'], '3.14 must stay float');
         $this->assertSame(42, $output['input_items_count']);
         $this->assertIsInt($output['input_items_count'], '42 must stay int');
-        $this->assertSame(3, $output['three_point_zero']);
+        $this->assertSame(3.0, $output['three_point_zero']); $this->assertIsFloat($output['three_point_zero']);
 
         $activityResult = $output['activity_result'];
         $this->assertSame('ORD-2', $activityResult['order_id']);
         $this->assertIsFloat($activityResult['amount'], 'activity result float must survive');
         $this->assertIsInt($activityResult['items_count'], 'activity result int must survive');
-        $this->assertSame(3, $activityResult['three_point_zero']);
+        $this->assertSame(3.0, $activityResult['three_point_zero']); $this->assertIsFloat($activityResult['three_point_zero']);
 
         $this->assertSame(['priority' => true, 'discount' => 0.15], $output['signal_payload']);
     }