Added mailboxes as local data sources (#1022)

app/MindWork AI Studio/Tools/Services/DataSourceEmbeddingRefreshMode.cs

@@ -0,0 +1,23 @@
+namespace AIStudio.Tools.Services;
+
+/// <summary>
+/// Why an indexing run of a data source was started.
+/// </summary>
+internal enum DataSourceEmbeddingRefreshMode
+{
+    STARTUP_HASH_CHECK,
+    HASH_CHECK,
+    WATCHER_HASH_CHECK,
+    MANUAL_RETRY,
+
+    /// <summary>
+    /// Carries on where the last run of the same data source stopped after its share of the work.
+    /// </summary>
+    CONTINUATION,
+
+    /// <summary>
+    /// The interval came round at which a data source is looked at again, since nothing reports its
+    /// changes, e.g. a mailbox on a server.
+    /// </summary>
+    INTERVAL_CHECK,
+}