lcameraDev: add resolve-only deviceSelector API and deduplicate resolve paths.

Export lcameraDev_resolveDeviceSelectorCReq for attach-identity consumers,
factor live-camera snapshot helpers, and share resolveDeviceSelectorAgainstRecords
with get-or-create session acquisition.

Co-authored-by: Cursor <cursoragent@cursor.com>

commonLibs/lcameraDev/selectorResolve.cpp

@@ -173,4 +173,13 @@ CameraIdentityRecord resolveSelectorAgainstRecords(
 	return *matches.front();
 }
 
+CameraIdentityRecord resolveDeviceSelectorAgainstRecords(
+	const std::string& deviceSelector,
+	const std::vector<CameraIdentityRecord>& records)
+{
+	const std::vector<SelectorCriterion> criteria =
+		parseDeviceSelector(deviceSelector);
+	return resolveSelectorAgainstRecords(criteria, records);
+}
+
 } // namespace lcamera_dev