fix(crypto): Bip39.TryParse must not throw on unrecognisable text

Wordlist.AutoDetect lands on NBitcoin's internal "Unknown" language for
text resembling no wordlist and throws NotSupportedException instead
of failing gracefully — found by fuzzing the restore-mnemonic input.
TryParse now treats that (and the same failure mode from the Mnemonic
constructor) as "not a valid mnemonic", consistent with every other
rejection path.

tests/PalladiumWallet.Tests/Crypto/Bip39Tests.cs

@@ -126,4 +126,15 @@ public class Bip39Tests
         Assert.Throws<ArgumentOutOfRangeException>(
             () => Bip39.Generate(MnemonicLength.Twelve, (MnemonicLanguage)99));
     }
+
+    [Fact]
+    public void Testo_che_non_somiglia_a_nessuna_wordlist_viene_rifiutato_senza_eccezioni()
+    {
+        // NBitcoin's Wordlist.AutoDetect throws NotSupportedException("Unknown")
+        // for text resembling no wordlist instead of failing gracefully (found by
+        // fuzzing): TryParse must swallow it and return false — this string reaches
+        // TryParse straight from the user's restore input.
+        Assert.False(Bip39.TryParse("ábÊco ábaco0ábaco ábÊ", out var mnemonic));
+        Assert.Null(mnemonic);
+    }
 }