refactor(sdk): remove deprecated v1 split build/sign transaction surface

packages/kotlin-sdk/KotlinExampleApp/TEST_PLAN.md

@@ -101,7 +101,7 @@ Most Platform actions have hard preconditions. Establish these fixtures before s
 | CORE-07 | SPV sync (start / stop / progress) | Core | Essential | ✅ | | Global sync indicator (`GlobalSyncIndicator`) → `platform_wallet_manager_spv_*`. Headers/filters/masternodes advance to tip. |
 | CORE-08 | QR scan recipient | Core | Manual | ✅ | | `QrScannerScreen` (CameraX), reachable in the Send flow. Emulators can use a virtual camera scene but reliability varies — treat as `Tier=Manual`. |
 | CORE-09 | Multiple HD accounts (within one wallet) | Core | Common | ✅ | | Account selection / `AccountDetailScreen`; balances per `account_index`. |
-| CORE-10 | Multi-recipient Core send | Core | Common | ✅ | | Send flow (`SendTransactionScreen`, Core→Core) → "Add recipient" appends extra address/amount rows → `CoreTransactionBuilder` (one `addOutput` per recipient) → `core_wallet_broadcast_transaction`. One tx with N outputs. |
+| CORE-10 | Multi-recipient Core send | Core | Common | ✅ | | Send flow (`SendTransactionScreen`, Core→Core) → "Add recipient" appends extra address/amount rows → `CoreTransactionBuilder` (one `addOutput` per recipient) → `finalizeAtomic` + `core_wallet_broadcast_signed_transaction_v2`. One tx with N outputs. |
 
 #### Multiple wallets on one device
 

packages/kotlin-sdk/sdk/src/main/kotlin/org/dashfoundation/dashsdk/ffi/NativePersistenceBridge.kt

@@ -721,8 +721,8 @@ class WalletRestoreData(
      *
      * Without this, a restored UTXO on an address BEYOND the gap window
      * has no derivation-path mapping, so `managed.address_derivation_path`
-     * (called from `core_wallet_tx_builder_build_signed`) fails and the
-     * wallet cannot sign a core-to-core spend after a cold restart. Mirror
+     * (resolved during the signing finalizers) fails and the wallet cannot
+     * sign a core-to-core spend after a cold restart. Mirror
      * of the Swift `buildCoreAddressPoolBuffer` slice on `loadWalletList`.
      */
     @JvmField val coreAddressPools: Array<CoreAddressPoolRestoreData>,

packages/kotlin-sdk/sdk/src/main/kotlin/org/dashfoundation/dashsdk/ffi/WalletManagerNative.kt

@@ -134,15 +134,14 @@ internal object WalletManagerNative {
     // `packages/kotlin-sdk/CLAUDE.md`); the `CoreTransactionBuilder` Kotlin
     // class orchestrates the sequence, mirroring the Swift
     // `CoreTransactionBuilder` + the `.coreToCore` flow in
-    // `SendViewModel.swift`. `builder` and `tx` are opaque native pointers
-    // carried as `Long` (the builder's `FFITransactionBuilder`, and a
-    // heap-boxed `FFICoreTransaction` from [coreTxBuilderBuildSigned]).
+    // `SendViewModel.swift`. `builder` is an opaque native pointer (the
+    // builder's `FFITransactionBuilder`) carried as `Long`.
 
     /**
      * `core_wallet_tx_builder_new` — create a builder for [network]
      * (`Network.ffiValue`). Returns the builder pointer (0 after throwing);
-     * free with [coreTxBuilderDestroy] or [coreTxBuilderBuildSigned] (which
-     * consumes it).
+     * free with [coreTxBuilderDestroy] or the consuming finalizers
+     * [coreTxBuilderFinalize] / [coreWalletFinalizeSignedPayment].
      */
     external fun coreTxBuilderNew(network: Int): Long
 
@@ -163,8 +162,8 @@ internal object WalletManagerNative {
 
     /**
      * `core_wallet_tx_builder_set_change_address` — override the change
-     * address (network-checked). Optional; the Core→Core send relies on
-     * [coreTxBuilderSetFunding], which also sets a change address.
+     * address (network-checked). Optional; the finalizers pick a change
+     * address themselves during funding selection.
      */
     external fun coreTxBuilderSetChangeAddress(builder: Long, address: String)
 
@@ -179,7 +178,7 @@ internal object WalletManagerNative {
      * `core_wallet_tx_builder_change_to_first_input` — route change to the
      * address of the first selected input (VIN0). MAYACHAIN identifies the
      * depositor by VIN0 and pays refunds there. Overrides the change address
-     * [coreTxBuilderSetFunding] assigned.
+     * funding selection assigned.
      */
     external fun coreTxBuilderChangeToFirstInput(builder: Long)
 
@@ -200,35 +199,7 @@ internal object WalletManagerNative {
      */
     external fun coreTxBuilderSetCurrentHeight(builder: Long, height: Int)
 
-    /**
-     * `core_wallet_tx_builder_set_funding` — fund from a wallet account,
-     * setting inputs AND the change address. [accountType]: 0 BIP44,
-     * 1 BIP32, 2 CoinJoin.
-     */
-    external fun coreTxBuilderSetFunding(
-        builder: Long,
-        walletHandle: Long,
-        accountType: Int,
-        accountIndex: Int,
-    )
-
-    /**
-     * `core_wallet_tx_builder_build_signed` — build + sign against the wallet
-     * account, resolving Core ECDSA signatures via [coreSignerHandle] (a
-     * `MnemonicResolverHandle`). CONSUMES the builder (do not reuse the
-     * builder handle afterwards). Returns an opaque built-transaction pointer
-     * (0 after throwing) for [coreWalletBroadcastTransaction] /
-     * [coreTransactionFree].
-     */
-    external fun coreTxBuilderBuildSigned(
-        builder: Long,
-        walletHandle: Long,
-        accountType: Int,
-        accountIndex: Int,
-        coreSignerHandle: Long,
-    ): Long
-
-    /** Atomic V2 finalizer; consumes [builder] and returns an opaque registry handle. */
+    /** Atomic V2 finalizer; consumes [builder] and returns an opaque signed-transaction V2 handle. */
     external fun coreTxBuilderFinalize(
         builder: Long,
         walletHandle: Long,
@@ -239,14 +210,16 @@ internal object WalletManagerNative {
 
     /**
      * `core_wallet_tx_builder_destroy` — free a builder from [coreTxBuilderNew]
-     * that was NOT consumed by [coreTxBuilderBuildSigned]. Safe on 0.
+     * that was NOT consumed by [coreTxBuilderFinalize] /
+     * [coreWalletFinalizeSignedPayment]. Safe on 0.
      */
     external fun coreTxBuilderDestroy(builder: Long)
 
     /**
      * `platform_wallet_get_core` — resolve the transient core-wallet handle
-     * from a `PlatformWallet` handle, for [coreWalletBroadcastTransaction].
-     * Free with [coreWalletDestroy]. Returns 0 after throwing.
+     * from a `PlatformWallet` handle, for
+     * [coreWalletBroadcastSignedTransactionV2]. Free with [coreWalletDestroy].
+     * Returns 0 after throwing.
      */
     external fun platformWalletGetCore(walletHandle: Long): Long
 
@@ -272,19 +245,6 @@ internal object WalletManagerNative {
         coreSignerHandle: Long,
     ): String
 
-    /**
-     * `core_wallet_broadcast_transaction` — broadcast a transaction built by
-     * [coreTxBuilderBuildSigned]. [accountType]/[accountIndex] identify the
-     * funding account so a definitive rejection releases its UTXO
-     * reservation. Returns the txid as a lowercase hex string.
-     */
-    external fun coreWalletBroadcastTransaction(
-        coreHandle: Long,
-        tx: Long,
-        accountType: Int,
-        accountIndex: Int,
-    ): String
-
     /**
      * `core_wallet_next_receive_address` — the engine's next unused BIP-44
      * EXTERNAL (receive) address for [accountIndex], base58-encoded.
@@ -324,13 +284,6 @@ internal object WalletManagerNative {
     /** `core_wallet_destroy` — release a core handle from [platformWalletGetCore]. Safe on 0. */
     external fun coreWalletDestroy(coreHandle: Long)
 
-    /**
-     * `core_wallet_transaction_free` — free a transaction from
-     * [coreTxBuilderBuildSigned] (its box AND the tx bytes it owns). Safe on
-     * 0; call exactly once per built transaction.
-     */
-    external fun coreTransactionFree(tx: Long)
-
     /**
      * `core_wallet_signed_payment_finalize` — atomically fund, reserve, sign,
      * AND register a builder for deferred (BIP70/BIP270) submission in one

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

@@ -24,9 +24,7 @@ import java.util.concurrent.atomic.AtomicLong
  * [ManagedPlatformWallet.sendToAddresses] (immediate broadcast) and
  * [ManagedPlatformWallet.buildSignedPayment] (deferred BIP70/BIP270 flows and
  * MAYACHAIN-style deposits — the option parameters there thread [addOpReturn],
- * [preserveOutputOrder] and [changeToFirstInput] into the build). The old
- * [setFunding] + [buildSigned] sequence remains only as a deprecated ABI
- * compatibility path and is not used by SDK convenience sends.
+ * [preserveOutputOrder] and [changeToFirstInput] into the build).
  *
  * @param network the wallet network — output and change addresses are
  *   validated against it Rust-side.
@@ -118,51 +116,6 @@ class CoreTransactionBuilder internal constructor(network: Network) : AutoClosea
         WalletManagerNative.coreTxBuilderSetCurrentHeight(handle, height)
     }
 
-    /** Fund from the account's UTXOs and set its change address. */
-    @Deprecated("Use finalizeAtomic; split funding/signing is not concurrency-safe")
-    internal fun setFunding(
-        wallet: ManagedPlatformWallet,
-        accountType: AccountType,
-        accountIndex: Int,
-    ): CoreTransactionBuilder = apply {
-        WalletManagerNative.coreTxBuilderSetFunding(
-            handle,
-            wallet.handle,
-            accountType.ffiValue,
-            accountIndex,
-        )
-    }
-
-    /**
-     * Build + sign against the account; returns the signed transaction
-     * WITHOUT broadcasting. CONSUMES the builder (it is freed Rust-side and
-     * this instance must not be reused afterwards).
-     *
-     * @param coreSignerHandle a `MnemonicResolverHandle` (the manager's
-     *   resolver) used for the Core ECDSA signatures.
-     */
-    @Deprecated("Use finalizeAtomic; split funding/signing is not concurrency-safe")
-    internal fun buildSigned(
-        wallet: ManagedPlatformWallet,
-        accountType: AccountType,
-        accountIndex: Int,
-        coreSignerHandle: Long,
-    ): CoreTransaction {
-        val builderPtr = handleRef.getAndSet(0)
-        check(builderPtr != 0L) { "CoreTransactionBuilder has been consumed or closed" }
-        // The FFI frees the builder on every path — mark it consumed (the
-        // AtomicLong swap above) so [close] / the cleaner never double-free
-        // it, matching Swift's `consumed = true` before the check.
-        val txPtr = WalletManagerNative.coreTxBuilderBuildSigned(
-            builderPtr,
-            wallet.handle,
-            accountType.ffiValue,
-            accountIndex,
-            coreSignerHandle,
-        )
-        return CoreTransaction(txPtr, accountType, accountIndex)
-    }
-
     /**
      * Consume this configured builder, atomically select and reserve inputs,
      * then sign after Rust has released its wallet-manager lock.
@@ -199,11 +152,10 @@ class CoreTransactionBuilder internal constructor(network: Network) : AutoClosea
     /**
      * Consume this configured builder and, in ONE atomic native operation,
      * select + reserve + sign the inputs and register the built transaction for
-     * deferred (BIP70/BIP270) submission. The concurrency-safe replacement for
-     * the deprecated [setFunding] + [buildSigned] + register split: selection
-     * and reservation commit as a single unit under the wallet-manager lock, so
-     * concurrent deferred builds cannot double-select an input. Returns the
-     * decoded [ManagedPlatformWallet.SignedCoreTransaction].
+     * deferred (BIP70/BIP270) submission. Selection and reservation commit as
+     * a single unit under the wallet-manager lock, so concurrent deferred
+     * builds cannot double-select an input. Returns the decoded
+     * [ManagedPlatformWallet.SignedCoreTransaction].
      */
     internal fun finalizeSignedPayment(
         wallet: ManagedPlatformWallet,
@@ -295,42 +247,3 @@ class FinalizedCoreTransaction internal constructor(handle: Long, val fee: Long)
         }
     }
 }
-
-/**
- * A built, signed core transaction — Android port of Swift's `CoreTransaction`.
- * Broadcast it via [ManagedCoreWallet.broadcastTransaction]; its native bytes
- * are freed on [close] or a [NativeCleaner] backstop.
- *
- * @property accountType the funding account captured at build time —
- *   [ManagedCoreWallet.broadcastTransaction] forwards it so a failed
- *   broadcast releases the UTXO reservation `buildSigned` took.
- */
-class CoreTransaction internal constructor(
-    handle: Long,
-    val accountType: CoreTransactionBuilder.AccountType,
-    val accountIndex: Int,
-) : AutoCloseable {
-
-    private val handleRef = AtomicLong(handle)
-    private val cleanable = NativeCleaner.register(this, TransactionCleanup(handleRef))
-
-    /** Opaque native `FFICoreTransaction` pointer; throws if already freed. */
-    internal val handle: Long
-        get() = handleRef.get().also {
-            check(it != 0L) { "CoreTransaction has been freed" }
-        }
-
-    override fun close() {
-        cleanable.clean()
-    }
-
-    /** Frees the native transaction (box + tx bytes) exactly once. */
-    private class TransactionCleanup(private val handleRef: AtomicLong) : Runnable {
-        override fun run() {
-            val handle = handleRef.getAndSet(0)
-            if (handle != 0L) {
-                WalletManagerNative.coreTransactionFree(handle)
-            }
-        }
-    }
-}

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

@@ -27,21 +27,6 @@ class ManagedCoreWallet internal constructor(handle: Long) : AutoCloseable {
             check(it != 0L) { "ManagedCoreWallet has been closed" }
         }
 
-    /**
-     * Broadcast a transaction built by [CoreTransactionBuilder.buildSigned].
-     * The funding account captured at build time is forwarded so a definitive
-     * broadcast rejection releases the UTXO reservation `buildSigned` took.
-     * Returns the txid as a lowercase hex string.
-     */
-    @Deprecated("Use the atomic FinalizedCoreTransaction send path")
-    fun broadcastTransaction(tx: CoreTransaction): String =
-        WalletManagerNative.coreWalletBroadcastTransaction(
-            handle,
-            tx.handle,
-            tx.accountType.ffiValue,
-            tx.accountIndex,
-        )
-
     /** Consume and broadcast a V2 finalized transaction. */
     fun broadcastTransaction(tx: FinalizedCoreTransaction): String =
         WalletManagerNative.coreWalletBroadcastSignedTransactionV2(
@@ -98,8 +83,8 @@ class ManagedCoreWallet internal constructor(handle: Long) : AutoCloseable {
      * The engine's next unused BIP-44 INTERNAL (change) address for
      * [accountIndex], base58-encoded — the change-side twin of
      * [nextReceiveAddress]; same used-set semantics and cold-start
-     * caveat. Builds pick change themselves (`setFunding`); this
-     * accessor exists for callers that must NAME a change address
+     * caveat. Builds pick change themselves during funding selection;
+     * this accessor exists for callers that must NAME a change address
      * up front (e.g. `CoreTransactionBuilder.setChangeAddress`).
      */
     fun nextChangeAddress(accountIndex: Int = 0): String {

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

@@ -156,8 +156,8 @@ class ManagedPlatformWallet internal constructor(
         }
         mapNativeErrors {
             val builder = CoreTransactionBuilder(network)
-            // `buildSigned` consumes the builder; `use` still safely destroys
-            // it on the pre-build failure paths (addOutput / setFunding throw).
+            // `finalizeAtomic` consumes the builder; `use` still safely
+            // destroys it on the pre-finalize failure paths (addOutput throws).
             val signedTx = builder.use {
                 for ((address, amount) in recipients) {
                     it.addOutput(address, amount)
@@ -287,8 +287,8 @@ class ManagedPlatformWallet internal constructor(
      * `new → addOutput* → finalizeSignedPayment` build runs under the same
      * per-wallet teardown gate ([gate]) as [sendToAddresses]. The single atomic
      * finalize does select + reserve + sign + register under the wallet-manager
-     * lock (closing the funding/signing selection race the old setFunding +
-     * buildSigned split had), so once this returns the reservation holds the
+     * lock (closing the funding/signing selection race the former split
+     * fund-then-sign path had), so once this returns the reservation holds the
      * inputs and [broadcastSigned] / [releaseReservation] operate on the token
      * later.
      *