chore: import upstream snapshot with attribution

examples/storage/spiffs/pytest_spiffs_example.py

@@ -0,0 +1,27 @@
+# SPDX-FileCopyrightText: 2022-2025 Espressif Systems (Shanghai) CO LTD
+# SPDX-License-Identifier: Unlicense OR CC0-1.0
+import re
+
+import pytest
+from pytest_embedded import Dut
+from pytest_embedded_idf.utils import idf_parametrize
+
+
+@pytest.mark.generic
+@idf_parametrize('target', ['esp32', 'esp32c3'], indirect=['target'])
+def test_examples_spiffs(dut: Dut) -> None:
+    message_list = (
+        rb'example: Initializing SPIFFS',
+        rb'example: Partition size: total: \d+, used: \d+',
+        rb'example: Opening file',
+        rb'example: File written',
+        rb'example: Renaming file',
+        rb'example: Reading file',
+        rb'example: Read from file: \'Hello World!\'',
+        rb'example: SPIFFS unmounted',
+    )
+
+    # First boot format + remount can exceed 60s on CI UART runners; keep startup fail-fast.
+    dut.expect(re.compile(message_list[0]), timeout=30)
+    for msg in message_list[1:]:
+        dut.expect(re.compile(msg), timeout=120)