fix(chat): route back navigation to history (#809)

app/src/main/java/com/m57/hermescontrol/Navigation.kt

@@ -1,5 +1,6 @@
 package com.m57.hermescontrol
 
+import androidx.activity.compose.BackHandler
 import androidx.compose.foundation.background
 import androidx.compose.foundation.layout.Box
 import androidx.compose.foundation.layout.Row
@@ -156,6 +157,10 @@ fun MainNavigation(sessionId: String? = null) {
 
     val openDrawer: () -> Unit = { scope.launch { drawerState.open() } }
 
+    BackHandler(enabled = currentScreen == ChatScreen && backStack.size == 1) {
+        NavigationController.goBack()
+    }
+
     CompositionLocalProvider(LocalDrawerGestureController provides gestureController) {
         ModalNavigationDrawer(
             drawerState = drawerState,