feat: send from contact details

app/src/main/java/com/bitcointxoko/gudariwallet/ui/WalletViewModel.kt

@@ -23,6 +23,7 @@ import com.bitcointxoko.gudariwallet.ui.receive.ReceiveViewModel
 import com.bitcointxoko.gudariwallet.ui.send.SendEvent
 import com.bitcointxoko.gudariwallet.ui.send.SendStrings
 import com.bitcointxoko.gudariwallet.ui.send.SendViewModel
+import kotlinx.coroutines.flow.MutableStateFlow
 import kotlinx.coroutines.flow.SharingStarted
 import kotlinx.coroutines.flow.map
 import kotlinx.coroutines.flow.stateIn
@@ -116,6 +117,16 @@ class WalletViewModel(
 
     val sendEvents: SharedFlow<SendEvent> = sendVm.events
 
+    // ── Contact tap-to-pay prefill ────────────────────────────────────────────
+    private val _pendingSend = MutableStateFlow<String?>(null)
+    val pendingSend: StateFlow<String?> get() = _pendingSend
+
+    /** Called by ContactDetailScreen before navigating to the Send tab. */
+    fun prefillSend(address: String) { _pendingSend.value = address }
+
+    /** Called by SendScreen once it has consumed the prefilled address. */
+    fun consumePendingSend() { _pendingSend.value = null }
+
     fun handleWithdrawScanned(raw: LnurlScanResponse, lnurl: String) {
         receiveVm.handleWithdrawResponse(raw, lnurl)
     }