Merge port/v4.1/split-build-broadcast into followup/v4.1/v2-handle-age-guard

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

Author: QuantumExplorer

packages/kotlin-sdk/sdk/src/main/kotlin/org/dashfoundation/dashsdk/wallet/ManagedCoreWallet.kt

@@ -89,6 +89,8 @@ class ManagedCoreWallet internal constructor(handle: Long) : AutoCloseable {
      */
     internal fun broadcastSignedPayment(token: Long): String =
         WalletManagerNative.coreWalletBroadcastSignedPayment(handle, token)
+
+    /**
      * The engine's next unused BIP-44 EXTERNAL (receive) address for
      * [accountIndex], base58-encoded — Android port of Swift's
      * `ManagedCoreWallet.nextReceiveAddress(accountIndex:)`

packages/kotlin-sdk/sdk/src/main/kotlin/org/dashfoundation/dashsdk/wallet/ManagedPlatformWallet.kt

@@ -356,6 +356,11 @@ class ManagedPlatformWallet internal constructor(
                     accountIndex,
                     coreSignerHandle,
                 )
+            }
+        }
+    }
+
+    /**
      * Sign [message] with the private key behind [address] and return the
      * signature as base64 — a **classic Dash signed message**, byte-for-byte
      * compatible with dashj's `ECKey.signMessage` and Dash Core's `signmessage`
@@ -527,6 +532,9 @@ class ManagedPlatformWallet internal constructor(
         } finally {
             java.lang.ref.Reference.reachabilityFence(payment)
         }
+    }
+
+    /**
      * Whether every UTF-16 surrogate in this string is part of a well-formed
      * high/low pair — i.e. whether the string has an exact UTF-8 encoding.
      *