Use display-friendly sync mode values (CalDAV, API, Manual)

These values are shown directly to users in HA, so casing matters.
Also fixes sensor.py which was comparing against hardcoded lowercase
literals instead of the constants.

Note: existing config entries storing old lowercase values will need
to be reconfigured.

custom_components/room_cal_ha/const.py

@@ -19,9 +19,9 @@ CONF_RESERVATION_DEFAULTS = "reservation_defaults"
 CONF_API_TOKEN = "api_token"
 
 # Sync mode values
-SYNC_MODE_CALDAV = "caldav"
-SYNC_MODE_API = "api"
-SYNC_MODE_MANUAL = "manual"
+SYNC_MODE_CALDAV = "CalDAV"
+SYNC_MODE_API = "API"
+SYNC_MODE_MANUAL = "Manual"
 
 # iCal event selection and data extraction
 RESERVATION_TITLE_PREFIX = "Guest: "

custom_components/room_cal_ha/sensor.py

@@ -87,9 +87,9 @@ class SyncSourceSensor(SensorEntity):
   @property
   def extra_state_attributes(self) -> dict[str, str | None]:
     mode = self._entry.options.get(CONF_SYNC_MODE, SYNC_MODE_MANUAL)
-    if mode == "caldav":
+    if mode == SYNC_MODE_CALDAV:
       url = self._entry.options.get(CONF_CALDAV_URL)
-    elif mode == "api":
+    elif mode == SYNC_MODE_API:
       url = self._entry.options.get(CONF_API_BASE_URL)
     else:
       url = None