refactor: narrow ViewModel injections, add ConnectionAware, delete dead code, integration tests

ViewModel Narrowing:
- V1: Created ConnectionAware interface; MessageSender, DeviceAdmin, DeviceControl extend it
- V2: Narrowed 6 ViewModels/actions to focused sub-interfaces (DeviceAdmin, MessageSender, DataRequester, DeviceControl)

Cleanup:
- C1: Deleted dead MeshDataMapper and its DI registration

Integration Tests:
- T2: SdkStateBridgeTest verifying WentOffline/CameOnline presence handling
- Verified Koin resolution, full test suite passes

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

core/model/src/commonMain/kotlin/org/meshtastic/core/model/ConnectionAware.kt

@@ -0,0 +1,24 @@
+/*
+ * Copyright (c) 2026 Meshtastic LLC
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+package org.meshtastic.core.model
+
+import kotlinx.coroutines.flow.StateFlow
+
+/** Provides read-only access to the app's connection state. */
+interface ConnectionAware {
+    val connectionState: StateFlow<ConnectionState>
+}

core/model/src/commonMain/kotlin/org/meshtastic/core/model/DeviceAdmin.kt

@@ -20,7 +20,7 @@ import org.meshtastic.proto.Channel
 import org.meshtastic.proto.Config
 
 /** Focused interface for local device configuration and edit sessions. */
-interface DeviceAdmin {
+interface DeviceAdmin : ConnectionAware {
     suspend fun setLocalConfig(config: Config)
     suspend fun setLocalChannel(channel: Channel)
     suspend fun beginEditSettings(destNum: Int)

core/model/src/commonMain/kotlin/org/meshtastic/core/model/DeviceControl.kt

@@ -17,7 +17,7 @@
 package org.meshtastic.core.model
 
 /** Focused interface for device lifecycle control. */
-interface DeviceControl {
+interface DeviceControl : ConnectionAware {
     suspend fun reboot(destNum: Int, packetId: Int)
     suspend fun rebootToDfu(nodeNum: Int)
     suspend fun requestRebootOta(requestId: Int, destNum: Int, mode: Int, hash: ByteArray?)

core/model/src/commonMain/kotlin/org/meshtastic/core/model/MessageSender.kt

@@ -17,7 +17,7 @@
 package org.meshtastic.core.model
 
 /** Focused interface for sending messages over the mesh. */
-interface MessageSender {
+interface MessageSender : ConnectionAware {
     suspend fun sendMessage(packet: DataPacket)
     fun getPacketId(): Int
 }

core/model/src/commonMain/kotlin/org/meshtastic/core/model/RadioController.kt

@@ -26,18 +26,6 @@ import org.meshtastic.proto.ClientNotification
  * This super-interface remains for backward compatibility with existing injections.
  */
 interface RadioController : MessageSender, DeviceAdmin, RemoteAdmin, DeviceControl, DataRequester {
-    /**
-     * Canonical app-level connection state, delegated from [ServiceRepository][connectionState].
-     *
-     * This exposes the same single source of truth as `ServiceRepository.connectionState`, surfaced through the
-     * controller interface for convenience in feature modules and ViewModels that depend on [RadioController] rather
-     * than [ServiceRepository] directly.
-     *
-     * This is **not** the transport-level state — it reflects the fully reconciled app-level state including handshake
-     * progress and device sleep policy.
-     */
-    val connectionState: StateFlow<ConnectionState>
-
     /**
      * Flow of notifications from the radio client.
      *

core/model/src/commonMain/kotlin/org/meshtastic/core/model/util/MeshDataMapper.kt

@@ -1,55 +0,0 @@
-/*
- * Copyright (c) 2026 Meshtastic LLC
- *
- * This program is free software: you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation, either version 3 of the License, or
- * (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program.  If not, see <https://www.gnu.org/licenses/>.
- */
-@file:Suppress("MagicNumber")
-
-package org.meshtastic.core.model.util
-
-import okio.ByteString.Companion.toByteString
-import org.meshtastic.core.model.DataPacket
-import org.meshtastic.proto.MeshPacket
-
-/**
- * Utility class to map [MeshPacket] protobufs to [DataPacket] domain models.
- *
- * This class is platform-agnostic and can be used in shared logic.
- */
-open class MeshDataMapper(private val nodeIdLookup: NodeIdLookup) {
-
-    /** Maps a [MeshPacket] to a [DataPacket], or returns null if the packet has no decoded data. */
-    open fun toDataPacket(packet: MeshPacket): DataPacket? {
-        val decoded = packet.decoded ?: return null
-        return DataPacket(
-            from = packet.from,
-            to = packet.to,
-            time = packet.rx_time * 1000L,
-            id = packet.id,
-            dataType = decoded.portnum.value,
-            bytes = decoded.payload.toByteArray().toByteString(),
-            hopLimit = packet.hop_limit,
-            channel = if (packet.pki_encrypted == true) DataPacket.PKC_CHANNEL_INDEX else packet.channel,
-            wantAck = packet.want_ack == true,
-            hopStart = packet.hop_start,
-            snr = packet.rx_snr,
-            rssi = packet.rx_rssi,
-            replyId = decoded.reply_id,
-            relayNode = packet.relay_node,
-            viaMqtt = packet.via_mqtt == true,
-            emoji = decoded.emoji,
-            transportMechanism = packet.transport_mechanism.value,
-        )
-    }
-}