DRY pass #2, batch 6, F19: BackButton, the arrow out of a full-screen surface (#5372)

Panel.kt BackButton(onClick, label): the IconButton + ArrowBack that the
tags, sync and editor top bars each built. Each keeps its own spoken
label. Checked with ktlint in the CI image.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

android/app/src/main/java/com/fabledsword/inkwell/ui/EditorChrome.kt

@@ -14,7 +14,6 @@ import androidx.compose.foundation.layout.navigationBarsPadding
 import androidx.compose.foundation.layout.padding
 import androidx.compose.foundation.shape.CircleShape
 import androidx.compose.material.icons.Icons
-import androidx.compose.material.icons.automirrored.filled.ArrowBack
 import androidx.compose.material.icons.automirrored.filled.List
 import androidx.compose.material.icons.filled.Check
 import androidx.compose.material.icons.filled.Close
@@ -96,12 +95,7 @@ fun EditorTopBar(
             // The only way out, and the only thing that needed a "save" button
             // before writes became continuous. Leaving IS saving now, which is what
             // the line in the bottom corner is there to say out loud.
-            IconButton(onClick = onClose) {
-                Icon(
-                    Icons.AutoMirrored.Filled.ArrowBack,
-                    contentDescription = stringResource(R.string.editor_back),
-                )
-            }
+            BackButton(onClose, R.string.editor_back)
         },
         actions = {
             if (!readOnly && owner) {

android/app/src/main/java/com/fabledsword/inkwell/ui/Panel.kt

@@ -9,8 +9,12 @@ import androidx.compose.foundation.layout.Column
 import androidx.compose.foundation.layout.fillMaxWidth
 import androidx.compose.foundation.layout.padding
 import androidx.compose.foundation.shape.RoundedCornerShape
+import androidx.compose.material.icons.Icons
+import androidx.compose.material.icons.automirrored.filled.ArrowBack
 import androidx.compose.material3.AlertDialog
 import androidx.compose.material3.DropdownMenuItem
+import androidx.compose.material3.Icon
+import androidx.compose.material3.IconButton
 import androidx.compose.material3.MaterialTheme
 import androidx.compose.material3.Text
 import androidx.compose.material3.TextButton
@@ -175,6 +179,17 @@ fun ConfirmDialog(
     )
 }
 
+/** The arrow out of a full-screen surface, at the start of its top bar. */
+@Composable
+fun BackButton(
+    onClick: () -> Unit,
+    @StringRes label: Int,
+) {
+    IconButton(onClick = onClick) {
+        Icon(Icons.AutoMirrored.Filled.ArrowBack, contentDescription = stringResource(label))
+    }
+}
+
 /** Secondary text under a field or a heading: smaller, and in the quieter ink. */
 @Composable
 fun Hint(

android/app/src/main/java/com/fabledsword/inkwell/ui/SyncScreen.kt

@@ -9,13 +9,9 @@ import androidx.compose.foundation.layout.imePadding
 import androidx.compose.foundation.layout.padding
 import androidx.compose.foundation.rememberScrollState
 import androidx.compose.foundation.verticalScroll
-import androidx.compose.material.icons.Icons
-import androidx.compose.material.icons.automirrored.filled.ArrowBack
 import androidx.compose.material3.Button
 import androidx.compose.material3.CircularProgressIndicator
 import androidx.compose.material3.ExperimentalMaterial3Api
-import androidx.compose.material3.Icon
-import androidx.compose.material3.IconButton
 import androidx.compose.material3.LinearProgressIndicator
 import androidx.compose.material3.MaterialTheme
 import androidx.compose.material3.Scaffold
@@ -76,14 +72,7 @@ fun SyncScreen(
         topBar = {
             TopAppBar(
                 title = { Text(stringResource(R.string.sync_title)) },
-                navigationIcon = {
-                    IconButton(onClick = onClose) {
-                        Icon(
-                            Icons.AutoMirrored.Filled.ArrowBack,
-                            contentDescription = stringResource(R.string.editor_back),
-                        )
-                    }
-                },
+                navigationIcon = { BackButton(onClose, R.string.editor_back) },
             )
         },
     ) { padding ->

android/app/src/main/java/com/fabledsword/inkwell/ui/TagsScreen.kt

@@ -19,7 +19,6 @@ import androidx.compose.foundation.shape.CircleShape
 import androidx.compose.foundation.text.KeyboardActions
 import androidx.compose.foundation.text.KeyboardOptions
 import androidx.compose.material.icons.Icons
-import androidx.compose.material.icons.automirrored.filled.ArrowBack
 import androidx.compose.material.icons.filled.MoreVert
 import androidx.compose.material3.AlertDialog
 import androidx.compose.material3.DropdownMenu
@@ -104,14 +103,7 @@ fun TagsScreen(
         topBar = {
             TopAppBar(
                 title = { Text(stringResource(R.string.tags_title)) },
-                navigationIcon = {
-                    IconButton(onClick = onClose) {
-                        Icon(
-                            Icons.AutoMirrored.Filled.ArrowBack,
-                            contentDescription = stringResource(R.string.tags_back),
-                        )
-                    }
-                },
+                navigationIcon = { BackButton(onClose, R.string.tags_back) },
             )
         },
     ) { padding ->