fix(log): TalkBack could not find the mode row

The tappable mode row used a bare `clickable`, which declares no role. TalkBack read it as
two pieces of text with nothing to say it could be activated, so the only way to correct a
wrong mode was invisible to anyone using a screen reader - and the row had just become the
only way to reach that field.

Role.Button plus an onClickLabel naming the action. The label lives in the resource files
like every other user-visible string.

Caught by self-review against the project's own accessibility pattern in Components.kt
rather than by a test; Compose UI is not unit-tested here, so this class of defect is only
ever found by reading.

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

@@ -58,6 +58,7 @@ import androidx.compose.runtime.saveable.rememberSaveable
 import androidx.compose.runtime.rememberCoroutineScope
 import androidx.compose.runtime.setValue
 import androidx.compose.ui.Alignment
+import androidx.compose.ui.semantics.Role
 import androidx.compose.ui.Modifier
 import androidx.compose.ui.draw.clip
 import androidx.compose.ui.graphics.Color
@@ -279,6 +280,7 @@ private fun ExpandedLogInput(
     // 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) }
+    val editModeLabel = stringResource(id = R.string.wavelog_mode_edit)
     // 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
@@ -442,7 +444,9 @@ private fun ExpandedLogInput(
                     // 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 }
+                    // Role.Button so TalkBack announces it as interactive. A bare clickable
+                    // declares no role, so the row read as two labels and the tap was undiscoverable.
+                    .clickable(role = Role.Button, onClickLabel = editModeLabel) { modeEditable = true }
                     .padding(horizontal = LocalSpacing.current.extraExtraSmall)
             ) {
                 Text(