feat: import leftover student fields into notes and show them on the roster

Store leftover CSV columns on hidden student notes, move catalog import to /events/import, and persist Students index columns from Chapter Settings.

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

Core/Services/INoteNamingService.cs

@@ -35,4 +35,19 @@ public interface INoteNamingService
     /// <param name="noteTitle">The note title to check</param>
     /// <returns>True if the note is a meeting note, false otherwise</returns>
     bool IsMeetingNote(string noteTitle);
+
+    /// <summary>
+    /// Gets the title for a student note. Format: "#Student:{id}"
+    /// </summary>
+    string GetStudentNoteTitle(int studentId);
+
+    /// <summary>
+    /// Checks if a note title is a student note.
+    /// </summary>
+    bool IsStudentNote(string? noteTitle);
+
+    /// <summary>
+    /// Parses the student id from a student note title.
+    /// </summary>
+    bool TryParseStudentNoteId(string? noteTitle, out int studentId);
 }