✨ Add file policy reset helpers

bitlogger/BitLogger_test.mbt

@@ -355,9 +355,46 @@ test "configured logger file setters update file sink policy state" {
   inspect(state.append, content="false")
   inspect(state.auto_flush, content="false")
   inspect(state.rotation is None, content="true")
+  inspect(logger.file_reset_policy(), content="true")
+  inspect(logger.file_append_mode(), content="true")
+  inspect(logger.file_auto_flush(), content="true")
+  inspect(logger.file_rotation_config() is None, content="true")
   ignore(logger.close())
 }
 
+test "configured logger reset policy restores configured file defaults" {
+  let logger = build_logger(
+    LoggerConfig::new(
+      sink=SinkConfig::new(
+        kind=SinkKind::File,
+        path="config-reset-policy.log",
+        append=false,
+        auto_flush=false,
+        rotation=Some(file_rotation(36, max_backups=2)),
+      ),
+    ),
+  )
+  inspect(logger.file_set_append_mode(true), content="true")
+  inspect(logger.file_set_auto_flush(true), content="true")
+  inspect(logger.file_clear_rotation(), content="true")
+  inspect(logger.file_reset_policy(), content="true")
+  inspect(logger.file_append_mode(), content="false")
+  inspect(logger.file_auto_flush(), content="false")
+  match logger.file_rotation_config() {
+    Some(rotation) => {
+      inspect(rotation.max_bytes, content="36")
+      inspect(rotation.max_backups, content="2")
+    }
+    None => inspect(false, content="true")
+  }
+  ignore(logger.close())
+}
+
+test "configured non-file logger cannot reset file policy" {
+  let logger = build_logger(LoggerConfig::new(sink=SinkConfig::new(kind=SinkKind::Console)))
+  inspect(logger.file_reset_policy(), content="false")
+}
+
 test "configured logger can reopen built file sink" {
   let logger = build_logger(
     LoggerConfig::new(