fix: improve chain support and error handling

- WalletManager.importWalletFromMnemonic: add support for TRON, FILECOIN,
  DASH, DOGECOIN, BCH, BSV (previously only ETH, BTC, LTC, EOS)
- WalletManager.importWalletFromMnemonic: throw on unsupported chain
  instead of silently returning null → NPE
- V3Keystore: add Filecoin support via FilecoinAddressCreator
- V3Keystore: improve error message for unsupported chain types
- Update .gitignore with more comprehensive patterns

Co-authored-by: Galaxy <GalaxySciTech@users.noreply.github.com>

Author: cursoragent

.gitignore

@@ -1,13 +1,30 @@
+# Gradle
 .gradle/
 build/
+/build
+/*/build/
+
+# IDE
 .settings/
 .project
 .classpath
-*.class
-.idea
+.idea/
 *.iml
-/local.properties
-.DS_Store
-/build
+*.ipr
+*.iws
+.vscode/
+
+# Compiled
+*.class
 /*/out/
-out
+out/
+
+# OS
+.DS_Store
+Thumbs.db
+
+# Properties
+/local.properties
+
+# Test output
+bin/

src/main/java/org/consenlabs/tokencore/wallet/WalletManager.java

@@ -167,16 +167,23 @@ public static Wallet importWalletFromMnemonic(Metadata metadata, @Nullable Strin
         MnemonicUtil.validateMnemonics(mnemonicCodes);
         switch (metadata.getChainType()) {
             case ChainType.ETHEREUM:
+            case ChainType.TRON:
+            case ChainType.FILECOIN:
                 keystore = V3MnemonicKeystore.create(metadata, password, mnemonicCodes, path);
                 break;
             case ChainType.BITCOIN:
-                keystore = HDMnemonicKeystore.create(metadata, password, mnemonicCodes, path);
-                break;
             case ChainType.LITECOIN:
+            case ChainType.DASH:
+            case ChainType.DOGECOIN:
+            case ChainType.BITCOINCASH:
+            case ChainType.BITCOINSV:
                 keystore = HDMnemonicKeystore.create(metadata, password, mnemonicCodes, path);
                 break;
             case ChainType.EOS:
                 keystore = EOSKeystore.create(metadata, password, accountName, mnemonicCodes, path, permissions);
+                break;
+            default:
+                throw new TokenException(String.format("Mnemonic import not supported for chain: %s", metadata.getChainType()));
         }
 
         return persistWallet(keystore, overwrite);

src/main/java/org/consenlabs/tokencore/wallet/keystore/V3Keystore.java

@@ -5,10 +5,7 @@
 import org.consenlabs.tokencore.foundation.crypto.Crypto;
 import org.consenlabs.tokencore.foundation.utils.MetaUtil;
 import org.consenlabs.tokencore.foundation.utils.NumericUtil;
-import org.consenlabs.tokencore.wallet.address.BitcoinAddressCreator;
-import org.consenlabs.tokencore.wallet.address.EthereumAddressCreator;
-import org.consenlabs.tokencore.wallet.address.SegWitBitcoinAddressCreator;
-import org.consenlabs.tokencore.wallet.address.TronAddressCreator;
+import org.consenlabs.tokencore.wallet.address.*;
 import org.consenlabs.tokencore.wallet.model.ChainType;
 import org.consenlabs.tokencore.wallet.model.Metadata;
 import org.consenlabs.tokencore.wallet.model.TokenException;
@@ -55,8 +52,12 @@ public V3Keystore(Metadata metadata, String password, String prvKeyHex, String i
             prvKeyBytes = NumericUtil.hexToBytes(prvKeyHex);
             new PrivateKeyValidator(prvKeyHex).validate();
             this.address = new TronAddressCreator().fromPrivateKey(prvKeyBytes);
-        }else {
-            throw new TokenException("Can't init eos keystore in this constructor");
+        } else if (metadata.getChainType().equals(ChainType.FILECOIN)) {
+            prvKeyBytes = NumericUtil.hexToBytes(prvKeyHex);
+            new PrivateKeyValidator(prvKeyHex).validate();
+            this.address = new FilecoinAddressCreator().fromPrivateKey(prvKeyBytes);
+        } else {
+            throw new TokenException(String.format("Unsupported chain type for V3Keystore: %s", metadata.getChainType()));
         }
         this.crypto = Crypto.createPBKDF2Crypto(password, prvKeyBytes);
         metadata.setWalletType(Metadata.V3);