test: make stylesheet tests platform-independent

app-desktop/src/test/kotlin/kst4contest/view/compose/PaletteStoreFactoryTest.kt

@@ -100,11 +100,11 @@ class PaletteStoreFactoryTest(@TempDir private val tempDir: Path) {
         val files = OperatorProfilePaletteFiles.of(other)
 
         assertTrue(
-            files.dayFile.path.endsWith("profiles/OP2/KST4ContestDefaultDay.css"),
+            files.dayFile.toPath().endsWith(Path.of("profiles", "OP2", "KST4ContestDefaultDay.css")),
             "the daylight file is ${files.dayFile.path}",
         )
         assertTrue(
-            files.eveningFile.path.endsWith("profiles/OP2/KST4ContestDefaultEvening.css"),
+            files.eveningFile.toPath().endsWith(Path.of("profiles", "OP2", "KST4ContestDefaultEvening.css")),
             "the evening file is ${files.eveningFile.path}",
         )
     }

app-desktop/src/test/kotlin/kst4contest/view/compose/tabs/StylesheetExportTest.kt

@@ -93,12 +93,16 @@ class StylesheetExportTest {
 
     @Test
     fun anUnwritablePlaceIsReportedRatherThanThrown() {
-        val target = File("/proc/kst4contest-cannot-write-here/day.css")
+        val blockingFile = Files.createTempFile("kst4contest-export-blocked-parent", ".tmp").toFile()
-
+        try {
+            val target = File(blockingFile, "day.css")
             val outcome = exportShippedStylesheet(target, darkMode = false)
 
             assertTrue(outcome is StylesheetExportOutcome.Failed, "outcome was $outcome")
             assertNotNull((outcome as StylesheetExportOutcome.Failed).reason)
+        } finally {
+            blockingFile.delete()
+        }
     }
 
     @Test