Add sidebar filter "first review today"

ftl/core/browsing.ftl

@@ -146,6 +146,7 @@ browsing-studied-today = Studied
 browsing-added-today = Added
 browsing-again-today = Again
 browsing-edited-today = Edited
+browsing-sidebar-first-review = First Review
 browsing-sidebar-due-today = Due
 browsing-sidebar-untagged = Untagged
 browsing-sidebar-overdue = Overdue

qt/aqt/browser/sidebar/tree.py

@@ -513,6 +513,12 @@ class SidebarTreeView(QTreeView):
             type=type,
             search_node=SearchNode(rated=SearchNode.Rated(days=1)),
         )
+        root.add_simple(
+            name=tr.browsing_sidebar_first_review(),
+            icon=icon,
+            type=type,
+            search_node=SearchNode(introduced_in_days=1),
+        )
         root.add_simple(
             name=tr.browsing_again_today(),
             icon=icon,

rslib/backend.proto

@@ -872,6 +872,7 @@ message SearchNode {
     int32 due_on_day = 16;
     string tag = 17;
     string note = 18;
+    uint32 introduced_in_days = 19;
   }
 }
 

rslib/src/backend/search/search_node.rs

@@ -49,6 +49,7 @@ impl TryFrom<pb::SearchNode> for Node {
                     ease: rated.rating().into(),
                 }),
                 Filter::AddedInDays(u) => Node::Search(SearchNode::AddedInDays(u)),
+                Filter::IntroducedInDays(u) => Node::Search(SearchNode::IntroducedInDays(u)),
                 Filter::DueInDays(i) => Node::Search(SearchNode::Property {
                     operator: "<=".to_string(),
                     kind: PropertyKind::Due(i),