fix(llm): 🐛 fix long Memo Tag issue on Cardano (#8608)

* fix(llm): fix long memo issue on Cardano

* chore: update change log

.changeset/rare-schools-happen.md

@@ -0,0 +1,5 @@
+---
+"live-mobile": minor
+---
+
+Truncate Cardano memos in the input to prevent the transaction validation errors

apps/ledger-live-mobile/src/families/cardano/MemoTagInput.tsx

@@ -3,10 +3,17 @@ import React from "react";
 import type { Transaction as CardanoTransaction } from "@ledgerhq/live-common/families/cardano/types";
 import type { MemoTagInputProps } from "LLM/features/MemoTag/types";
 import { GenericMemoTagInput } from "LLM/features/MemoTag/components/GenericMemoTagInput";
+import { truncateUtf8 } from "LLM/utils/truncateUtf8";
 
 export default (props: MemoTagInputProps<CardanoTransaction>) => (
   <GenericMemoTagInput
     {...props}
+    textToValue={text => truncateUtf8(text, MAX_MEMO_LENGTH)}
     valueToTxPatch={value => tx => ({ ...tx, memo: value || undefined })}
   />
 );
+
+// From the Cardano metadata documentation:
+// > Strings must be at most 64 bytes when UTF-8 encoded.
+// https://developers.cardano.org/docs/get-started/cardano-serialization-lib/transaction-metadata/#metadata-limitations
+const MAX_MEMO_LENGTH = 64;