fix: revert LogEntry to 7-arg constructor (source is not a ctor param)

LogEntry.getSource() exists but source is not a constructor parameter
in cameleer3-common — it uses a default value.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

cameleer3-server-app/src/test/java/com/cameleer3/server/app/search/ClickHouseLogStoreIT.java

@@ -49,7 +49,7 @@ class ClickHouseLogStoreIT {
 
     private LogEntry entry(Instant ts, String level, String logger, String message,
                            String thread, String stackTrace, Map<String, String> mdc) {
-        return new LogEntry(ts, level, logger, message, thread, stackTrace, mdc, "app");
+        return new LogEntry(ts, level, logger, message, thread, stackTrace, mdc);
     }
 
     private LogSearchRequest req(String application) {