fix: clear stale speedtest_latest from dashboard on server wipe

Add clear_speedtest_latest() to web.py to reset in-memory state.
Called when remote server is reachable but has no results.

Author: itsDNNS

app/modules/speedtest/collector.py

@@ -58,6 +58,7 @@ def collect(self) -> CollectorResult:
                     # Remote reachable but empty — server was wiped
                     log.info("Remote has no results but cache has %d, clearing", cached_count)
                     self._storage.clear_cache()
+                    self._web.clear_speedtest_latest()
                     cached_count = 0
                 elif results and results[0].get("id", 0) < last_id:
                     log.info(

app/web.py

@@ -657,6 +657,12 @@ def update_state(analysis=None, error=None, poll_interval=None, connection_info=
             _state["weather_latest"] = weather_latest
 
 
+def clear_speedtest_latest():
+    """Clear the cached speedtest_latest from state (e.g. after server reset)."""
+    with _state_lock:
+        _state["speedtest_latest"] = None
+
+
 def get_state() -> dict:
     """Return a snapshot of the shared web state (thread-safe)."""
     with _state_lock: