Add initial support for Icom IC-705 radio

- Added support for Icom IC-705 radio model with split mode functionality.
- Updated RadioTrackingService to handle single-radio split mode and dual-radio configurations.
- Modified MainContainer to provide appropriate radio controllers based on selected model.
- Enhanced SettingsRepo to include split mode preference in radio control settings.
- Updated UI in SettingsDialog to allow toggling of split mode for IC-705 and adjust device selection accordingly.
- Improved handling of baud rates based on selected radio model.
- Added extended operations in IRadioController for IC-705 specific commands.

core/domain/src/main/java/com/rtbishop/look4sat/core/domain/model/Settings.kt

@@ -74,12 +74,20 @@ data class RadioControlSettings(
     val rxRadioAddress: String,
     val txRadioName: String,
     val rxRadioName: String,
-    val baudRate: Int
+    val baudRate: Int,
+    /** IC-705 only: use single-radio split-VFO mode instead of two radios. */
+    val splitMode: Boolean = false
 ) {
     companion object {
-        val SUPPORTED_RADIOS = listOf(
-            "Yaesu FT-817/818",
-            "Yaesu FT-857/897"
-        )
+        const val MODEL_YAESU_FT817   = "Yaesu FT-817/818"
+        const val MODEL_YAESU_FT857   = "Yaesu FT-857/897"
+        const val MODEL_ICOM_IC705    = "Icom IC-705"
+
+        val SUPPORTED_RADIOS = listOf(MODEL_YAESU_FT817, MODEL_YAESU_FT857, MODEL_ICOM_IC705)
+
+        /** Baud rates available for Yaesu radios. */
+        val BAUD_RATES_YAESU = listOf(4800, 9600, 38400)
+        /** Baud rates available for Icom IC-705 (higher speeds supported via CI-V USB/BT). */
+        val BAUD_RATES_ICOM  = listOf(4800, 9600, 19200, 38400, 57600, 115200)
     }
 }

core/domain/src/main/java/com/rtbishop/look4sat/core/domain/repository/IRadioController.kt

@@ -38,4 +38,34 @@ interface IRadioController {
     suspend fun pttOn(): Boolean
 
     suspend fun pttOff(): Boolean
+
+    // ── Extended operations (IC-705 / CI-V) ──────────────────────────────
+
+    /**
+     * Read the current PTT status from the radio.
+     * Returns true if transmitting, false if receiving, null on error.
+     * Default: not supported.
+     */
+    suspend fun readPttStatus(): Boolean? = null
+
+    /**
+     * Select the active VFO.
+     * @param vfoA true → VFO-A (main/RX), false → VFO-B (sub/TX in split).
+     * Default: no-op.
+     */
+    suspend fun setVfo(vfoA: Boolean): Boolean = false
+
+    /**
+     * Enable or disable SPLIT mode (TX on sub-VFO, RX on main VFO).
+     * Default: not supported.
+     */
+    suspend fun setSplitMode(enabled: Boolean): Boolean = false
+
+    /**
+     * Set the frequency of the currently active VFO.
+     * On radios that support it (IC-705: CMD 0x25 sub 0x00) this updates
+     * the active VFO without switching.
+     * Default: delegates to [setFrequency].
+     */
+    suspend fun setWorkingFrequency(frequencyHz: Long): Boolean = setFrequency(frequencyHz)
 }