feat(lora): honor a pinned-preset intent advertised for UNSET (#6711)

Co-authored-by: Claude Opus 5 <noreply@anthropic.com>

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

@@ -82,6 +82,9 @@ fun LoRaRegionPresetMap?.repairPresetFor(region: RegionCode, current: ModemPrese
  * [current] is the [ModemPreset.LONG_FAST] placeholder a factory-flashed node reports (proto default), the region's
  * advertised default is adopted instead (the firmware map's when present, else the app's built-in default). Any other
  * preset at UNSET was set deliberately (e.g. a vendor build pinning USERPREFS_LORACONFIG_MODEM_PRESET) and is kept.
+ *
+ * A build that pins a preset can also advertise it as an UNSET map entry (firmware #11507), stating outright that the
+ * preset is deliberate; that keeps even a pinned LONG_FAST, which the placeholder heuristic alone cannot distinguish.
  */
 fun LoRaRegionPresetMap?.presetForRegionChange(
     previousRegion: RegionCode,
@@ -89,7 +92,8 @@ fun LoRaRegionPresetMap?.presetForRegionChange(
     current: ModemPreset,
 ): ModemPreset {
     val repaired = repairPresetFor(newRegion, current)
-    val freshSetup = previousRegion == RegionCode.UNSET && current == ModemPreset.LONG_FAST
+    val pinned = constraintFor(RegionCode.UNSET) != null
+    val freshSetup = previousRegion == RegionCode.UNSET && !pinned && current == ModemPreset.LONG_FAST
     return if (freshSetup) {
         // Re-repair the adopted default: a malformed map's advertised default may not be in its own legal set.
         val preferred = constraintFor(newRegion)?.defaultPreset ?: defaultPresetFor(newRegion) ?: repaired

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

@@ -213,4 +213,35 @@ class LoRaRegionPresetsTest {
             oddMap.presetForRegionChange(RegionCode.UNSET, RegionCode.US, ModemPreset.LONG_FAST),
         )
     }
+
+    // A pinned build advertises its preset as UNSET's map entry (firmware #11507): the same fixture plus a
+    // single-preset UNSET group, here stating a deliberate LONG_FAST pin.
+    private val pinnedMap =
+        map.copy(
+            groups =
+            map.groups +
+                LoRaPresetGroup(
+                    presets = listOf(ModemPreset.LONG_FAST),
+                    default_preset = ModemPreset.LONG_FAST,
+                    licensed_only = false,
+                ),
+            region_groups = map.region_groups + LoRaRegionPresets(region = RegionCode.UNSET, group_index = 3),
+        )
+
+    @Test
+    fun `an UNSET map entry marks even a LongFast pin as deliberate at fresh setup`() {
+        // Without the entry this placeholder would adopt EU_N_868's MEDIUM_FAST default (asserted above).
+        assertEquals(
+            ModemPreset.LONG_FAST,
+            pinnedMap.presetForRegionChange(RegionCode.UNSET, RegionCode.EU_N_868, ModemPreset.LONG_FAST),
+        )
+    }
+
+    @Test
+    fun `a pin stated via UNSET entry is still repaired when illegal in the region`() {
+        assertEquals(
+            ModemPreset.TINY_FAST,
+            pinnedMap.presetForRegionChange(RegionCode.UNSET, RegionCode.UA_433, ModemPreset.LONG_FAST),
+        )
+    }
 }

feature/settings/src/commonMain/kotlin/org/meshtastic/feature/settings/radio/component/LoRaConfigItemList.kt

@@ -169,7 +169,11 @@ fun LoRaConfigScreen(viewModel: RadioConfigViewModel, onBack: () -> Unit) {
                 val regionPresetMap = if (capabilities.supportsLoraRegionPresetMap) state.loraRegionPresetMap else null
                 val presetConstraint =
                     remember(regionPresetMap, formState.value.region) {
-                        regionPresetMap.constraintFor(formState.value.region)
+                        // UNSET's map entry states pin intent (firmware #11507), not a constraint: never let it
+                        // narrow the picker while the region is still unset.
+                        formState.value.region
+                            .takeIf { it != RegionCode.UNSET }
+                            ?.let { regionPresetMap.constraintFor(it) }
                     }
                 val presetsGated = presetConstraint?.isGated(state.localIsLicensed) == true
                 DropDownPreference(