fix: add AuthorizeCall signed extension for PezkuwiChain

PezkuwiChain requires AuthorizeCall as the first signed extension in
the TxExtension tuple. This commit adds:

- AuthorizeCall.kt: FixedValueTransactionExtension with empty payload
  (PhantomData equivalent)
- CustomTransactionExtensions: Detects PezkuwiChain via metadata and
  adds AuthorizeCall extension
- ExtrinsicBuilderFactory/ExtrinsicSplitter: Uses CustomTransactionExtensions

Without this fix, transactions fail with "bad signature" errors and
fee calculation (payment_queryInfo) fails with WASM trap errors.

runtime/src/main/java/io/novafoundation/nova/runtime/extrinsic/CustomTransactionExtensions.kt

@@ -1,20 +1,54 @@
 package io.novafoundation.nova.runtime.extrinsic
 
+import io.novafoundation.nova.runtime.extrinsic.extensions.AuthorizeCall
 import io.novafoundation.nova.runtime.extrinsic.extensions.ChargeAssetTxPayment
 import io.novafoundation.nova.runtime.extrinsic.extensions.CheckAppId
+import io.novasama.substrate_sdk_android.runtime.RuntimeSnapshot
 import io.novasama.substrate_sdk_android.runtime.extrinsic.builder.ExtrinsicBuilder
 import io.novasama.substrate_sdk_android.runtime.extrinsic.v5.transactionExtension.TransactionExtension
 
 object CustomTransactionExtensions {
 
+    // PezkuwiChain genesis hashes (mainnet and teyrchains)
+    private val PEZKUWI_GENESIS_HASHES = setOf(
+        "bb4a61ab0c4b8c12f5eab71d0c86c482e03a275ecdafee678dea712474d33d75", // Pezkuwi Mainnet
+        "00d0e1d0581c3cd5c5768652d52f4520184018b44f56a2ae1e0dc9d65c00c948", // Asset Hub
+        "58269e9c184f721e0309332d90cafc410df1519a5dc27a5fd9b3bf5fd2d129f8", // People Chain
+        "96eb58af1bb7288115b5e4ff1590422533e749293f231974536dc6672417d06f"  // Zagros Testnet
+    )
+
     fun applyDefaultValues(builder: ExtrinsicBuilder) {
         defaultValues().forEach(builder::setTransactionExtension)
     }
 
+    fun applyDefaultValues(builder: ExtrinsicBuilder, runtime: RuntimeSnapshot) {
+        defaultValues(runtime).forEach(builder::setTransactionExtension)
+    }
+
     fun defaultValues(): List<TransactionExtension> {
         return listOf(
             ChargeAssetTxPayment(),
             CheckAppId()
         )
     }
+
+    fun defaultValues(runtime: RuntimeSnapshot): List<TransactionExtension> {
+        val extensions = mutableListOf<TransactionExtension>()
+
+        // Add AuthorizeCall only for PezkuwiChain networks
+        if (isPezkuwiChain(runtime)) {
+            extensions.add(AuthorizeCall())
+        }
+
+        extensions.add(ChargeAssetTxPayment())
+        extensions.add(CheckAppId())
+
+        return extensions
+    }
+
+    private fun isPezkuwiChain(runtime: RuntimeSnapshot): Boolean {
+        val genesisHash = runtime.metadata.extrinsic.signedExtensions
+            .any { it.id == "AuthorizeCall" }
+        return genesisHash
+    }
 }

runtime/src/main/java/io/novafoundation/nova/runtime/extrinsic/ExtrinsicBuilderFactory.kt

@@ -56,7 +56,7 @@ class ExtrinsicBuilderFactory(
                 setTransactionExtension(CheckSpecVersion(metadataProof.usedVersion.specVersion))
                 setTransactionExtension(CheckTxVersion(metadataProof.usedVersion.transactionVersion))
 
-                CustomTransactionExtensions.defaultValues().forEach(::setTransactionExtension)
+                CustomTransactionExtensions.defaultValues(runtime).forEach(::setTransactionExtension)
             }
         }
     }

runtime/src/main/java/io/novafoundation/nova/runtime/extrinsic/extensions/AuthorizeCall.kt

@@ -0,0 +1,18 @@
+package io.novafoundation.nova.runtime.extrinsic.extensions
+
+import io.novasama.substrate_sdk_android.runtime.extrinsic.v5.transactionExtension.extensions.FixedValueTransactionExtension
+
+/**
+ * Signed extension for PezkuwiChain that authorizes calls.
+ * This extension uses PhantomData internally, so it has no payload (empty encoding).
+ *
+ * In the runtime, AuthorizeCall is defined as:
+ * pub struct AuthorizeCall<T>(core::marker::PhantomData<T>);
+ *
+ * It's placed first in the TxExtension tuple for PezkuwiChain.
+ */
+class AuthorizeCall : FixedValueTransactionExtension(
+    name = "AuthorizeCall",
+    implicit = null,
+    explicit = null  // PhantomData encodes to nothing
+)