test: migrate MigrationTest to runTest and add missing repository fakes

Part A — runBlocking → runTest
- Migrated all 5 runBlocking sites in core/database MigrationTest
  (@Before + 4 @Test bodies) to kotlinx.coroutines.test.runTest so
  test dispatchers are virtual-time aware and cancellation semantics
  match the rest of the suite.
- Left DatabaseManagerLegacyCleanupTest on runBlocking: it polls with
  delay(100) for async cleanup that runs on Dispatchers.IO. runTest's
  virtual-time delay would collapse instantly and race the real IO
  cleanup, so runBlocking is the correct choice there.

Part B — missing repository fakes
Added five in-memory fakes in core:testing (pure Kotlin, MutableStateFlow
backed) that implement their repository interface exactly:
- FakeDeviceHardwareRepository      (DeviceHardwareRepository)
- FakeFirmwareReleaseRepository     (FirmwareReleaseRepository)
- FakeQuickChatActionRepository     (QuickChatActionRepository)
- FakeTracerouteSnapshotRepository  (TracerouteSnapshotRepository)
- FakeRadioConfigRepository         (RadioConfigRepository)

Each fake is exercised by a new test in
core/testing/src/commonTest/kotlin/.../RepositoryFakesTest.kt:
upsert/delete/reorder flows for quick-chat, seeded lookups +
call-recording for device hardware, stable/alpha emission for
firmware releases, snapshot round-trips for traceroute, and
channel-set mutations for radio config. PacketRepository was
skipped — 40+ members and a FakePacketRepository helper already
exists for informal use; left for a focused follow-up.

Validation (all green):
  ./gradlew spotlessApply spotlessCheck
  ./gradlew :core:testing:jvmTest :core:database:testAndroid
  ./gradlew detekt kmpSmokeCompile

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

core/database/src/androidHostTest/kotlin/org/meshtastic/core/database/dao/MigrationTest.kt

@@ -20,7 +20,7 @@ import androidx.room3.Room
 import androidx.test.core.app.ApplicationProvider
 import androidx.test.ext.junit.runners.AndroidJUnit4
 import kotlinx.coroutines.flow.first
-import kotlinx.coroutines.runBlocking
+import kotlinx.coroutines.test.runTest
 import okio.ByteString.Companion.toByteString
 import org.junit.After
 import org.junit.Before
@@ -59,7 +59,7 @@ class MigrationTest {
         )
 
     @Before
-    fun createDb(): Unit = runBlocking {
+    fun createDb(): Unit = runTest {
         val context = ApplicationProvider.getApplicationContext<android.content.Context>()
         database =
             Room.inMemoryDatabaseBuilder<MeshtasticDatabase>(
@@ -77,7 +77,7 @@ class MigrationTest {
     }
 
     @Test
-    fun testMigrateChannelsByPSK_duplicatePSK() = runBlocking {
+    fun testMigrateChannelsByPSK_duplicatePSK() = runTest {
         // PSK \"AQ==\" is base64 for single byte 0x01
         val pskBytes = byteArrayOf(0x01).toByteString()
 
@@ -103,7 +103,7 @@ class MigrationTest {
     }
 
     @Test
-    fun testMigrateChannelsByPSK_reorder() = runBlocking {
+    fun testMigrateChannelsByPSK_reorder() = runTest {
         val pskA = byteArrayOf(0x01).toByteString()
         val pskB = byteArrayOf(0x02).toByteString()
 
@@ -122,7 +122,7 @@ class MigrationTest {
     }
 
     @Test
-    fun testMigrateChannelsByPSK_disambiguateByName() = runBlocking {
+    fun testMigrateChannelsByPSK_disambiguateByName() = runTest {
         val pskA = byteArrayOf(0x01).toByteString()
 
         insertPacket(channel = 0, text = "Msg A1")
@@ -141,7 +141,7 @@ class MigrationTest {
     }
 
     @Test
-    fun testMigrateChannelsByPSK_preferSameIndexIfStillAmbiguous() = runBlocking {
+    fun testMigrateChannelsByPSK_preferSameIndexIfStillAmbiguous() = runTest {
         val pskA = byteArrayOf(0x01).toByteString()
 
         insertPacket(channel = 0, text = "Msg A")