smartlist: allow filtering

peopleProxy is a QSortProxyFilter we can use to filter our smartlist
based on user input from the searchbar

Issue: #81111
Change-Id: I0dab38670e4f5f64d924effc81405d663d90dfeb
diff --git a/src/SmartViewVC.h b/src/SmartViewVC.h
index 1ef6594..8e2d988 100644
--- a/src/SmartViewVC.h
+++ b/src/SmartViewVC.h
@@ -19,6 +19,6 @@
 
 #import <Cocoa/Cocoa.h>
 
-@interface SmartViewVC : NSViewController
+@interface SmartViewVC : NSViewController <NSTextFieldDelegate>
 
 @end