fix: prevent meaningless ratio calculation for zero height in EmbedCode

src/EmbedCode.php

@@ -19,7 +19,7 @@ public function __construct(string $html, ?int $width = null, ?int $height = nul
         $this->width = $width;
         $this->height = $height;
 
-        if ($width !== null && $width !== 0 && $height !== null) {
+        if ($width !== null && $width !== 0 && $height !== null && $height !== 0) {
             $this->ratio = round(($height / $width) * 100, 3);
         }
     }

tests/EmbedCodeTest.php

@@ -38,9 +38,9 @@ public function testRatioCalculationWithNullHeight()
 
     public function testRatioCalculationWithZeroHeight()
     {
-        // height=0 case (ratio becomes 0.0)
+        // height=0 case (prevents meaningless ratio calculation)
         $code = new EmbedCode('<iframe></iframe>', 400, 0);
-        $this->assertEquals(0.0, $code->ratio);
+        $this->assertNull($code->ratio);
     }
 
     public function testRatioCalculationWithBothZero()