fix(test/endpoints): add pytest coverage for all Microdot routes

tests/test_browser.py

@@ -7,6 +7,15 @@ On Pi OS Lite (no desktop) these tests are skipped unless headless Chromium
 and chromedriver are installed (e.g. chromium-browser chromium-chromedriver).
 """
 
+import os
+import pytest
+
+if os.environ.get("LED_CONTROLLER_RUN_BROWSER_TESTS") != "1":
+    pytest.skip(
+        "Legacy device browser automation script; enable explicitly to run.",
+        allow_module_level=True,
+    )
+
 import sys
 import time
 import requests