fix(log): the mode field kept the previous transponder's value

Two things about the mode on the logging surface.

It was held in `remember` with no key, so switching transponder mid-session kept the mode
from the transponder before it. The operator saw the old value in the field and it went out
with the upload - a wrong mode nobody chose. It is now keyed on the transponder uuid.

It was also a text field the operator had to look at on every contact, when the value comes
from the transponder record anyway. A pass lasts eight minutes; the study on satellite
logging is blunt that the fast surface should carry one typed field, not two. The mode is
now shown as a row and the field appears when the row is tapped, because a transponder
record can be wrong and the operator still has to be able to say so.

The row is 48dp tall, which is the Material Design minimum for anything tappable. Vertical
padding alone had left it around 20dp - visually fine, awkward to hit, and a real problem
for anyone with reduced dexterity.

feature/radar/src/main/java/com/rtbishop/look4sat/feature/radar/LogTab.kt

@@ -16,6 +16,8 @@ import androidx.compose.animation.core.tween
 import androidx.compose.foundation.background
 import androidx.compose.foundation.clickable
 import androidx.compose.foundation.gestures.detectHorizontalDragGestures
+import com.rtbishop.look4sat.core.presentation.LocalSpacing
+import androidx.compose.foundation.layout.heightIn
 import androidx.compose.foundation.layout.Arrangement
 import androidx.compose.foundation.layout.Box
 import androidx.compose.foundation.layout.Column
@@ -273,7 +275,10 @@ private fun ExpandedLogInput(
     val context = androidx.compose.ui.platform.LocalContext.current
     val scope = rememberCoroutineScope()
     var callsign by remember { mutableStateOf("") }
-    var mode by remember { mutableStateOf(radio.uplinkMode ?: "FM") }
+    // Keyed on the transponder. Without the key, switching transponder mid-session kept the
+    // previous one's mode and uploaded a value the operator never chose.
+    var mode by remember(radio.uuid) { mutableStateOf(radio.uplinkMode ?: "FM") }
+    var modeEditable by remember(radio.uuid) { mutableStateOf(false) }
     // Calls logged during this pass, so a repeat can be mentioned without being blocked: the same
     // station on a later pass is a legitimate new contact. This replaces a 300ms window that
     // swallowed what it guessed were accidental double submissions - a guess that could discard
@@ -416,14 +421,38 @@ private fun ExpandedLogInput(
             textStyle = MaterialTheme.typography.bodyMedium,
             modifier = Modifier.fillMaxWidth()
         )
-        OutlinedTextField(
-            value = mode,
-            onValueChange = { mode = it.take(8) },
-            label = { Text(stringResource(id = R.string.wavelog_mode_hint)) },
-            singleLine = true,
-            textStyle = MaterialTheme.typography.bodyMedium,
-            modifier = Modifier.fillMaxWidth()
-        )
+        // The mode comes from the transponder, so it is shown rather than typed - one less field
+        // during a pass that lasts eight minutes. Tapping it reveals the field, because a
+        // transponder record can be wrong and the operator has to be able to say so.
+        if (modeEditable) {
+            OutlinedTextField(
+                value = mode,
+                onValueChange = { mode = it.take(8) },
+                label = { Text(stringResource(id = R.string.wavelog_mode_hint)) },
+                singleLine = true,
+                textStyle = MaterialTheme.typography.bodyMedium,
+                modifier = Modifier.fillMaxWidth()
+            )
+        } else {
+            Row(
+                horizontalArrangement = Arrangement.SpaceBetween,
+                verticalAlignment = Alignment.CenterVertically,
+                modifier = Modifier
+                    .fillMaxWidth()
+                    // 48dp is the Material Design minimum for anything tappable, and this row is
+                    // tapped to reveal the mode field. Padding alone left it around 20dp.
+                    .heightIn(min = 48.dp)
+                    .clickable { modeEditable = true }
+                    .padding(horizontal = LocalSpacing.current.extraExtraSmall)
+            ) {
+                Text(
+                    text = stringResource(id = R.string.wavelog_mode_hint),
+                    style = MaterialTheme.typography.bodySmall,
+                    color = MaterialTheme.colorScheme.onSurfaceVariant
+                )
+                Text(text = mode, style = MaterialTheme.typography.bodyMedium)
+            }
+        }
     }
 }