fix: read temp_unit from briefing_config not a nonexistent temperature_unit setting

src/fabledassistant/routes/briefing.py

@@ -130,7 +130,15 @@ async def recent_items():
 @_REQUIRE
 async def get_weather():
     rows = await weather_svc.get_cached_weather_rows(g.user.id)
-    temp_unit = await get_setting(g.user.id, "temperature_unit", "C")
+    import json as _json
+    raw = await get_setting(g.user.id, "briefing_config", "{}")
+    try:
+        _cfg = _json.loads(raw) if isinstance(raw, str) else (raw or {})
+        temp_unit = _cfg.get("temp_unit", "C")
+        if temp_unit not in ("C", "F"):
+            temp_unit = "C"
+    except Exception:
+        temp_unit = "C"
     cards = [
         card for row in rows
         if (card := weather_svc.parse_weather_card_data(row, temp_unit)) is not None