feat(misc): a bunch of crude UI/UX tweaks

- display add time for later use
- basic keyboard navigation support
- remember last-used server address
- show connection error when attempt to connect to server

dataitems/comicitem.cpp

@@ -8,6 +8,7 @@ ComicItem::ComicItem(QJsonObject jsonObj, const QString &name)
     setData(jsonObj["num_pages"].toInt(), PageCountRole);
     setData(jsonObj["current_page"].toInt(), CurrentPageRole);
     setData(jsonObj["type"].toInt(), TypeRole);
+    setData(jsonObj["added"].toInteger(), AddedTimeRole);
 }
 
 QHash<int, QByteArray> ComicItem::roleNames()
@@ -19,5 +20,6 @@ QHash<int, QByteArray> ComicItem::roleNames()
         {ComicItem::PageCountRole, "pageCount"},
         {ComicItem::CurrentPageRole, "currentPage"},
         {ComicItem::TypeRole, "type"},
+        {ComicItem::AddedTimeRole, "addedTime"},
     };
 }

dataitems/comicitem.h

@@ -14,6 +14,7 @@ public:
         PageCountRole,
         CurrentPageRole,
         TypeRole,
+        AddedTimeRole,
     };
     Q_ENUM(Roles)