fix: update consent text with Apache 2.0/CC-BY-4.0 and copyright retention

app.py

@@ -289,9 +289,10 @@ Write Python code in your native language using [Legesher](https://legesher.io)
 """
 
 CONSENT_TEXT = (
-    "I give permission for my submitted code to be used in the Language, Decoded research project "
-    "and to be published as part of an open dataset (Apache 2.0 / CC-BY-4.0). "
-    "No personal information is collected — submissions are anonymous."
+    "I confirm I am a native or fluent speaker of the selected language and wrote this code myself. "
+    "I grant permission for this code to be used in the Language, Decoded research project and "
+    "released as part of an open dataset under Apache 2.0 / CC-BY-4.0. "
+    "I retain copyright over my submission. No personal information is collected — submissions are anonymous."
 )
 
 SIDEBAR_MD = """