test: pin ModemPreset->channel-name contract; drop vacuous name check

Add ChannelPresetNameTest (commonTest, so it gates every PR) pinning
every ModemPreset to its exact firmware-canonical channel name from
DisplayFormatters::getModemPresetDisplayName(preset, useShortName=false).
The name is interop-critical (it feeds the channel hash, channel
number/frequency and MQTT topic), so the test:
- locks the mapping against accidental edits (e.g. "LongMod" ->
  "LongModerate"),
- asserts set-completeness vs ModemPreset.entries, so a new preset that
  was added to Channel.name's `when` but not pinned here fails loudly
  (also catches someone silencing the intentional compile tripwire with
  an `else`),
- covers the deprecated VERY_LONG_SLOW, which still has a real name.

This backstops Channel.name's exhaustive `when` without weakening it.
The numeric on-air anchors (hash/channelNum/radioFreq) stay in
ChannelTest. Remove the old androidDeviceTest allModemPresetsHaveValidNames,
which only asserted name != "Invalid" — a value the no-else `when` can
never produce, so it gave the illusion of a name guard while testing
nothing, and ran only on-device rather than on every PR.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

core/model/src/androidDeviceTest/kotlin/org/meshtastic/core/model/ChannelTest.kt

@@ -24,7 +24,6 @@ import org.meshtastic.core.model.util.CHANNEL_URL_PREFIX
 import org.meshtastic.core.model.util.getChannelUrl
 import org.meshtastic.core.model.util.toChannelSet
 import org.meshtastic.proto.ChannelSet
-import org.meshtastic.proto.Config
 
 @RunWith(AndroidJUnit4::class)
 class ChannelTest {
@@ -64,18 +63,4 @@ class ChannelTest {
 
         Assert.assertEquals(906.875f, ch.radioFreq)
     }
-
-    @Test
-    fun allModemPresetsHaveValidNames() {
-        Config.LoRaConfig.ModemPreset.entries.forEach { preset ->
-            // Skip UNRECOGNIZED if it exists (Wire generates it sometimes) or generic UNSET values if applicable
-            if (preset.name == "UNSET" || preset.name == "UNRECOGNIZED") return@forEach
-
-            val loraConfig = Channel.default.loraConfig.copy(use_preset = true, modem_preset = preset)
-            val channel = Channel(loraConfig = loraConfig)
-
-            // We want to ensure it is NOT "Invalid"
-            Assert.assertNotEquals("Preset ${preset.name} should typically have a valid name", "Invalid", channel.name)
-        }
-    }
 }

core/model/src/commonTest/kotlin/org/meshtastic/core/model/ChannelPresetNameTest.kt

@@ -0,0 +1,82 @@
+/*
+ * 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 org.meshtastic.proto.Config.LoRaConfig.ModemPreset
+import kotlin.test.Test
+import kotlin.test.assertEquals
+
+/**
+ * Contract test pinning the preset -> channel-name mapping in [Channel.name].
+ *
+ * This name is INTEROP-CRITICAL: for a channel with an empty name and `use_preset = true`, the name is hashed into the
+ * channel hash, the channel number / radio frequency, and the MQTT topic, so it must byte-match the firmware. Source of
+ * truth is firmware `DisplayFormatters::getModemPresetDisplayName(preset, useShortName = false)`. Two names are
+ * deliberately abbreviated (LONG_MODERATE -> "LongMod", VERY_LONG_SLOW -> "VLongSlow") and must NOT be auto-derived
+ * from the enum name.
+ *
+ * When firmware adds a preset, [Channel.name]'s exhaustive `when` fails to compile first (by design). This test is the
+ * backstop: it forces the new branch to carry the EXACT firmware name, guards the mapping against accidental edits, and
+ * fails if a preset is left unpinned (e.g. someone silenced the compile error with an `else`). It deliberately covers
+ * the deprecated VERY_LONG_SLOW, which still has a real firmware name. The numeric anchors (hash/channelNum/radioFreq)
+ * live in ChannelTest and are the genuine on-air interop guard — keep both.
+ */
+class ChannelPresetNameTest {
+
+    // Firmware-canonical names: DisplayFormatters::getModemPresetDisplayName(preset, useShortName = false).
+    private val expectedNames =
+        mapOf(
+            ModemPreset.SHORT_TURBO to "ShortTurbo",
+            ModemPreset.SHORT_FAST to "ShortFast",
+            ModemPreset.SHORT_SLOW to "ShortSlow",
+            ModemPreset.MEDIUM_FAST to "MediumFast",
+            ModemPreset.MEDIUM_SLOW to "MediumSlow",
+            ModemPreset.LONG_FAST to "LongFast",
+            ModemPreset.LONG_SLOW to "LongSlow",
+            ModemPreset.LONG_MODERATE to "LongMod",
+            ModemPreset.VERY_LONG_SLOW to "VLongSlow",
+            ModemPreset.LONG_TURBO to "LongTurbo",
+            ModemPreset.LITE_FAST to "LiteFast",
+            ModemPreset.LITE_SLOW to "LiteSlow",
+            ModemPreset.NARROW_FAST to "NarrowFast",
+            ModemPreset.NARROW_SLOW to "NarrowSlow",
+            ModemPreset.TINY_FAST to "TinyFast",
+            ModemPreset.TINY_SLOW to "TinySlow",
+        )
+
+    private fun presetChannelName(preset: ModemPreset): String =
+        Channel(loraConfig = Channel.default.loraConfig.copy(use_preset = true, modem_preset = preset)).name
+
+    @Test
+    fun every_preset_maps_to_its_exact_firmware_name() {
+        expectedNames.forEach { (preset, expected) ->
+            assertEquals(expected, presetChannelName(preset), "Channel name for $preset must match firmware exactly")
+        }
+    }
+
+    @Test
+    fun every_ModemPreset_is_pinned() {
+        val protoPresets = ModemPreset.entries.filter { it.name != "UNSET" && it.name != "UNRECOGNIZED" }.toSet()
+        assertEquals(
+            protoPresets,
+            expectedNames.keys,
+            "Every ModemPreset must be pinned to its firmware name here. A new preset was added to the protos " +
+                "(and to Channel.name's `when`) but not recorded in this contract — add it with its exact " +
+                "DisplayFormatters::getModemPresetDisplayName string.",
+        )
+    }
+}