Add offline and ntfy alerts

Co-authored-by: Copilot <[email protected]>

modules/app_dash.py

@@ -274,6 +274,47 @@ def _mounted_source(partition, mount_point, read_only):
     return mount_point, True, False
 
 
+def dashcam_storage_usage(mount_point=DEFAULT_MOUNT_POINT):
+    with _device_lock:
+        partition = find_dashcam_partition()
+        if partition is None:
+            return {"status": "no_device"}
+        source, mounted_here, _remounted = _mounted_source(
+            partition, mount_point, read_only=True
+        )
+        if source is None:
+            return {
+                "status": "mount_failed",
+                "path": partition["path"],
+            }
+        try:
+            usage = shutil.disk_usage(source)
+            used_percent = round(
+                usage.used / (usage.used + usage.free) * 100, 1
+            )
+            result = {
+                "status": "ok",
+                "path": partition["path"],
+                "total_bytes": usage.total,
+                "used_bytes": usage.used,
+                "free_bytes": usage.free,
+                "used_percent": used_percent,
+            }
+        except OSError as error:
+            result = {
+                "status": "read_failed",
+                "path": partition["path"],
+                "error": str(error),
+            }
+        finally:
+            if mounted_here and not unmount_device(mount_point):
+                result = {
+                    "status": "unmount_failed",
+                    "path": partition["path"],
+                }
+        return result
+
+
 def list_dashcam_files(mount_point=DEFAULT_MOUNT_POINT):
     """List video files on the detected dashcam without copying them."""
     with _device_lock: