refactor: consolidate metric formatting through MetricFormatter (#5169)

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
Co-authored-by: jamesarich <2199651+jamesarich@users.noreply.github.com>

core/common/src/commonMain/kotlin/org/meshtastic/core/common/util/MetricFormatter.kt

@@ -23,6 +23,7 @@ package org.meshtastic.core.common.util
  * All methods return locale-independent strings using [NumberFormatter] (dot decimal separator), which is intentional
  * for a mesh networking app where consistency matters.
  */
+@Suppress("TooManyFunctions")
 object MetricFormatter {
 
     fun temperature(celsius: Float, isFahrenheit: Boolean): String {
@@ -47,6 +48,12 @@ object MetricFormatter {
     fun snr(value: Float, decimalPlaces: Int = 1): String = "${NumberFormatter.format(value, decimalPlaces)} dB"
 
     fun rssi(value: Int): String = "$value dBm"
+
+    fun windSpeed(metersPerSecond: Float, decimalPlaces: Int = 1): String =
+        "${NumberFormatter.format(metersPerSecond, decimalPlaces)} m/s"
+
+    fun rainfall(millimeters: Float, decimalPlaces: Int = 1): String =
+        "${NumberFormatter.format(millimeters, decimalPlaces)} mm"
 }
 
 private const val FAHRENHEIT_SCALE = 1.8f

core/common/src/commonTest/kotlin/org/meshtastic/core/common/util/MetricFormatterTest.kt

@@ -120,4 +120,24 @@ class MetricFormatterTest {
     fun snrNegative() {
         assertEquals("-5.5 dB", MetricFormatter.snr(-5.5f))
     }
+
+    @Test
+    fun windSpeed() {
+        assertEquals("12.3 m/s", MetricFormatter.windSpeed(12.34f))
+    }
+
+    @Test
+    fun windSpeedZero() {
+        assertEquals("0.0 m/s", MetricFormatter.windSpeed(0.0f))
+    }
+
+    @Test
+    fun rainfall() {
+        assertEquals("2.5 mm", MetricFormatter.rainfall(2.54f))
+    }
+
+    @Test
+    fun rainfallZero() {
+        assertEquals("0.0 mm", MetricFormatter.rainfall(0.0f))
+    }
 }