feat: launch arg to start logged in as a supplied user (#5626)

src/providers/twitch/TwitchAccountManager.cpp

@@ -1,5 +1,7 @@
 #include "providers/twitch/TwitchAccountManager.hpp"
 
+#include "Application.hpp"
+#include "common/Args.hpp"
 #include "common/Common.hpp"
 #include "common/QLogging.hpp"
 #include "providers/twitch/api/Helix.hpp"
@@ -144,6 +146,11 @@ void TwitchAccountManager::reloadUsers()
 
 void TwitchAccountManager::load()
 {
+    if (getApp()->getArgs().initialLogin.has_value())
+    {
+        this->currentUsername = getApp()->getArgs().initialLogin.value();
+    }
+
     this->reloadUsers();
 
     this->currentUsername.connect([this](const QString &newUsername) {