fix: rethrow CancellationException in suspend catch blocks

Three suspend functions in BleRadioTransport caught Exception without
rethrowing CancellationException, which could silently swallow
coroutine cancellation:
- findDevice(): scan retry loop would continue even after cancellation
- attemptConnection(): bond() failure handler swallowed cancellation
- onConnected(): RSSI read failure handler swallowed cancellation
Also replace runCatching with safeCatching in two suspend contexts:
- RadioConfigViewModel.probeMqttConnection()
- LegacyDfuTransport DFU version read
Per project rules: use safeCatching in coroutine/suspend contexts,
keep runCatching only in cleanup/teardown or non-suspend code.

core/network/src/commonMain/kotlin/org/meshtastic/core/network/radio/BleRadioTransport.kt

@@ -182,6 +182,8 @@ class BleRadioTransport(
                         }
                     }
                 if (d != null) return d
+            } catch (e: CancellationException) {
+                throw e
             } catch (e: Exception) {
                 Logger.v(e) { "[$address] Scan attempt failed or timed out" }
             }
@@ -243,6 +245,8 @@ class BleRadioTransport(
             try {
                 bluetoothRepository.bond(device)
                 Logger.i { "[$address] Bonding successful" }
+            } catch (e: CancellationException) {
+                throw e
             } catch (e: Exception) {
                 Logger.w(e) { "[$address] Bonding failed, attempting connection anyway" }
             }
@@ -301,6 +305,8 @@ class BleRadioTransport(
                 val rssi = retryBleOperation(tag = address) { device.readRssi() }
                 Logger.d { "[$address] Connection confirmed. Initial RSSI: $rssi dBm" }
             }
+        } catch (e: CancellationException) {
+            throw e
         } catch (e: Exception) {
             Logger.w(e) { "[$address] Failed to read initial connection RSSI" }
         }

feature/firmware/src/commonMain/kotlin/org/meshtastic/feature/firmware/ota/dfu/LegacyDfuTransport.kt

@@ -142,7 +142,7 @@ class LegacyDfuTransport(
             // Best-effort DFU Version read — gate out unsupported old bootloaders (SDK ≤ 6).
             val versionChar = service.characteristic(LEGACY_DFU_VERSION_UUID)
             val version =
-                runCatching { service.read(versionChar) }
+                safeCatching { service.read(versionChar) }
                     .map { bytes ->
                         if (bytes.size >= 2) (bytes[0].toInt() and 0xFF) or ((bytes[1].toInt() and 0xFF) shl 8) else -1
                     }

feature/settings/src/commonMain/kotlin/org/meshtastic/feature/settings/radio/RadioConfigViewModel.kt

@@ -35,6 +35,7 @@ import org.jetbrains.compose.resources.StringResource
 import org.koin.core.annotation.InjectedParam
 import org.koin.core.annotation.KoinViewModel
 import org.meshtastic.core.common.util.CommonUri
+import org.meshtastic.core.common.util.safeCatching
 import org.meshtastic.core.domain.usecase.settings.AdminActionsUseCase
 import org.meshtastic.core.domain.usecase.settings.ExportProfileUseCase
 import org.meshtastic.core.domain.usecase.settings.ExportSecurityConfigUseCase
@@ -165,7 +166,7 @@ open class RadioConfigViewModel(
         probeJob =
             viewModelScope.launch {
                 val result =
-                    runCatching { mqttManager.probe(address, tlsEnabled, username, password) }
+                    safeCatching { mqttManager.probe(address, tlsEnabled, username, password) }
                         .getOrElse { e ->
                             Logger.w(e) { "MQTT probe threw" }
                             MqttProbeStatus.Other(message = e.message)