fix(infrared): allocate dedicated static slot for physically learned keys

domain/src/main/kotlin/com/flagship/abox/manager/domain/infrared/LearnVirtualRemoteKey.kt

@@ -25,14 +25,11 @@ class LearnVirtualRemoteKey(
         val binding = bindings.find { it.buttonId == buttonId }
             ?: return DomainResult.Failure(DomainError.InvalidRequest(detail = "Button not found"))
 
-        val targetSlot = when (remote.transmissionMode) {
-            TransmissionMode.STATIC_SLOTS -> {
-                binding.assignedSlot ?: run {
-                    // Find available slot from quota
-                    "1"
-                }
-            }
-            TransmissionMode.DYNAMIC_SCRATCH -> remote.dynamicScratchSlot
+        val targetSlot = binding.assignedSlot ?: run {
+            val allBindings = (repository.getKeyBindings(remoteId) as? DomainResult.Success)?.value.orEmpty()
+            val usedSlots = allBindings.mapNotNull { it.assignedSlot?.toIntOrNull() }.toSet()
+            val nextSlot = (1..99).firstOrNull { it !in usedSlots } ?: 1
+            nextSlot.toString()
         }
 
         // Set status to LEARNING while hardware listens

domain/src/main/kotlin/com/flagship/abox/manager/domain/infrared/SendVirtualRemoteAction.kt

@@ -37,16 +37,21 @@ class SendVirtualRemoteAction(
                 gateway.sendKey(profileId, remote.deviceName, slot)
             }
             TransmissionMode.DYNAMIC_SCRATCH -> {
-                val hexCode = binding.rawHexCode
-                    ?: return DomainResult.Failure(DomainError.InvalidRequest(detail = "No hex code available for dynamic transmission"))
+                if (binding.rawHexCode != null) {
                     // 1. Download to scratch slot
                     val scratchSlot = remote.dynamicScratchSlot
-                when (val dlResult = gateway.downloadCodes(profileId, listOf(InfraredCode(remote.deviceName, scratchSlot, hexCode)))) {
+                    when (val dlResult = gateway.downloadCodes(profileId, listOf(InfraredCode(remote.deviceName, scratchSlot, binding.rawHexCode)))) {
                         is DomainResult.Failure -> return dlResult
                         is DomainResult.Success -> Unit
                     }
                     // 2. Send scratch slot
                     gateway.sendKey(profileId, remote.deviceName, scratchSlot)
+                } else if (binding.assignedSlot != null) {
+                    // Fallback to sending learned hardware slot
+                    gateway.sendKey(profileId, remote.deviceName, binding.assignedSlot)
+                } else {
+                    DomainResult.Failure(DomainError.InvalidRequest(detail = "No hex code or slot available for transmission"))
+                }
             }
         }
     }