Parse Reblog root url in default .txt ingest mode

TraverseDirectory (the no-args ingest path) never read the "Reblog
root url:" line, so RootURL stayed unset even though AddPost/UpdatePost
already support it via the API-based --likes flow. New scraper output
now includes this field; wire it through both AddPost call sites.

URLNotesGrabberCORE/DataAccess.cs

@@ -37,6 +37,7 @@ namespace URLNotesGrabberCORE
         public string reblogKey;
         public string reblogName;
         public string reblogURL;
+        public string rootURL;
         public string slug;
         public string summary;
         public string tags;
@@ -60,6 +61,7 @@ namespace URLNotesGrabberCORE
             reblogKey = ".";
             reblogName = ".";
             reblogURL = ".";
+            rootURL = ".";
             slug = ".";
             summary = ".";
             tags = ".";