fix: make USB probing and eject flow safe

Author: jamakr4

app/src/main/java/com/drivehub/kamera/dashcam/DashcamStorageManager.java

@@ -434,20 +434,25 @@ private static boolean runWriteProbe(File dir) {
 
     /** Returns null when the probe wrote and read back, otherwise why it did not. */
     private static String writeProbeError(File dir) {
-        File probe = new File(dir, WRITE_PROBE_FILE_NAME);
+        File probe = null;
         try {
+            // resolve() can run concurrently from the settings screen and the recording loop.
+            // A fixed probe name lets one caller delete the other's file and creates a false
+            // WRITE_TEST_FAILED result, so every invocation needs its own temporary file.
+            probe = File.createTempFile(WRITE_PROBE_FILE_NAME + ".", ".tmp", dir);
             try (FileOutputStream out = new FileOutputStream(probe)) {
                 out.write("dashcam".getBytes());
                 out.getFD().sync();
             }
             boolean ok = probe.isFile() && probe.length() > 0;
-            // noinspection ResultOfMethodCallIgnored
-            probe.delete();
             return ok ? null : "file missing or empty after write";
         } catch (Throwable t) {
-            // noinspection ResultOfMethodCallIgnored
-            probe.delete();
             return String.valueOf(t);
+        } finally {
+            if (probe != null) {
+                // noinspection ResultOfMethodCallIgnored
+                probe.delete();
+            }
         }
     }
 

app/src/main/java/com/drivehub/kamera/dashcam/RecordingService.java

@@ -203,18 +203,15 @@ public int onStartCommand(Intent intent, int flags, int startId) {
             // Decide on the worker thread: resolve() touches the filesystem for every target
             // except INTERNAL_ONLY. That was harmless while the preference was pinned to
             // internal storage; now that it is honoured, this would be main-thread IO.
-            usbEjectInProgress = true;
-            shutdownRecordingServiceWithoutStopSelf();
             new Thread(() -> {
                 boolean usingUsb = activeBaseIsUsb || DashcamStorageManager.resolve(this).usingUsb;
                 if (!usingUsb) {
-                    usbEjectInProgress = false;
                     broadcastUsbEjectReady(
                             false, R.string.settings_dashcam_storage_eject_unavailable_message);
-                    stopForeground(true);
-                    stopSelf();
                     return;
                 }
+                usbEjectInProgress = true;
+                shutdownRecordingServiceWithoutStopSelf();
                 boolean safeToRemove = awaitShutdownQuiescence();
                 broadcastUsbEjectReady(
                         safeToRemove,