fix: apply skipValidation to all presets when set on parent

.changeset/healthy-windows-melt.md

@@ -0,0 +1,5 @@
+---
+"@t3-oss/env-core": minor
+---
+
+update skipValidation flag to skip validation for extended presets

docs/src/app/docs/customization/page.mdx

@@ -16,6 +16,8 @@ Skipping validation is not encouraged and will lead to your types and runtime va
 
 </Callout>
 
+When enabled, validation will be skipped for both your environment variables and any [extended presets](#extending-presets).
+
 ```ts title="src/env.ts"
 import { createEnv } from "@t3-oss/env-core";
 

packages/core/src/index.ts

@@ -324,7 +324,16 @@ export function createEnv<
   }
 
   const skip = !!opts.skipValidation;
-  if (skip) return runtimeEnv as any;
+  if (skip) {
+    if (opts.extends) {
+      for (const preset of opts.extends) {
+        preset.skipValidation = true;
+      }
+    }
+
+    // biome-ignore lint/suspicious/noExplicitAny: <explanation>
+    return runtimeEnv as any;
+  }
 
   const _client = typeof opts.client === "object" ? opts.client : {};
   const _server = typeof opts.server === "object" ? opts.server : {};