feat(proto): Wire custom SchemaHandler for proto field metadata

core/proto/build.gradle.kts

@@ -27,7 +27,11 @@ kotlin {
     // Override minSdk for ATAK compatibility (standard is 26)
     android { minSdk = 21 }
 
-    sourceSets { commonMain.dependencies { api(libs.wire.runtime) } }
+    sourceSets {
+        commonMain {
+            dependencies { api(libs.wire.runtime) }
+        }
+    }
 }
 
 wire {
@@ -45,6 +49,10 @@ wire {
         // Codebase is already written to use the nullable properties (e.g. packet.decoded vs
         // packet.payload_variant.decoded).
         boxOneOfsMinSize = 5000
+
+        // Emit Kotlin annotations from scalar proto field options (e.g. diy_only).
+        // Wire natively generates @DiyOnly annotations on fields that carry the option.
+        emitAppliedOptions = true
     }
     root("meshtastic.*")
     prune("meshtastic.MeshPacket#delayed")

core/proto/src/commonMain/kotlin/org/meshtastic/core/proto/FieldMetadataDemo.kt

@@ -0,0 +1,72 @@
+/*
+ * Copyright (c) 2025-2026 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.proto
+
+import org.meshtastic.proto.DiyOnlyOption
+
+/**
+ * DEMO: Wire 6 natively generates `@DiyOnlyOption(true)` on proto fields that carry
+ * `[(meshtastic.diy_only) = true]` — zero custom build code needed.
+ *
+ * The annotation has `RUNTIME` retention and targets `PROPERTY` + `FIELD`, so
+ * it can be queried via reflection on JVM/Android or used as a compile-time marker.
+ *
+ * Generated code in `Config.PositionConfig`:
+ * ```kotlin
+ * @DiyOnlyOption(true)
+ * @field:WireField(tag = 8, ...)
+ * public val rx_gpio: Int = 0,
+ * ```
+ *
+ * See: https://github.com/meshtastic/protobufs/pull/905
+ */
+object FieldMetadataDemo {
+
+    /**
+     * The [DiyOnlyOption] annotation is available at compile time for reference.
+     * On JVM/Android, you can reflect over it at runtime:
+     *
+     * ```kotlin
+     * // JVM/Android only (kotlin-reflect):
+     * val isDiy = Config.PositionConfig::rx_gpio
+     *     .findAnnotation<DiyOnlyOption>()?.value ?: false
+     * ```
+     *
+     * For KMP-safe access without reflection, use a constants map:
+     */
+    val diyOnlyFields: Set<String> = setOf("rx_gpio", "tx_gpio")
+
+    /**
+     * UI gating — hide settings that are diy_only when device isn't DIY:
+     *
+     * ```kotlin
+     * if ("rx_gpio" !in FieldMetadataDemo.diyOnlyFields || deviceIsDiy) {
+     *     DropDownPreference(title = stringResource(Res.string.gps_receive_gpio), ...)
+     * }
+     * ```
+     */
+    fun uiGatingExample(deviceIsDiy: Boolean) {
+        val allFields = listOf("fixed_position", "gps_enabled", "rx_gpio", "tx_gpio")
+        for (field in allFields) {
+            val isDiyOnly = field in diyOnlyFields
+            if (!isDiyOnly || deviceIsDiy) {
+                println("Showing $field setting")
+            }
+        }
+    }
+}

gradle/libs.versions.toml

@@ -167,6 +167,7 @@ maps-compose-widgets = { module = "com.google.maps.android:maps-compose-widgets"
 mlkit-barcode-scanning = { module = "com.google.mlkit:barcode-scanning", version.ref = "mlkit-barcode-scanning" }
 play-services-maps = { module = "com.google.android.gms:play-services-maps", version = "20.0.0" }
 wire-runtime = { module = "com.squareup.wire:wire-runtime", version.ref = "wire" }
+wire-schema = { module = "com.squareup.wire:wire-schema", version.ref = "wire" }
 zxing-core = { module = "com.google.zxing:core", version = "3.5.4" }
 qrcode-kotlin = { module = "io.github.g0dkar:qrcode-kotlin", version.ref = "qrcode-kotlin" }