HackStudio: set sane $PATH early to include /usr/local/bin

Launching from the terminal inherits $PATH which includes
/usr/local/bin, but launching from the system menubar doesn't, so
HackStudio wasn't finding make installed from ports.

DevTools/HackStudio/TerminalWrapper.cpp

@@ -105,7 +105,6 @@ void TerminalWrapper::run_command(const String& command)
         }
 
         setenv("TERM", "xterm", true);
-        setenv("PATH", "/bin:/usr/bin:/usr/local/bin", true);
 
         auto parts = command.split(' ');
         ASSERT(!parts.is_empty());

DevTools/HackStudio/main.cpp

@@ -10,6 +10,7 @@
 #include "TerminalWrapper.h"
 #include "WidgetTool.h"
 #include "WidgetTreeModel.h"
+#include <AK/StringBuilder.h>
 #include <LibCore/CFile.h>
 #include <LibGUI/GAboutDialog.h>
 #include <LibGUI/GAction.h>
@@ -121,6 +122,13 @@ int main(int argc, char** argv)
     widget->set_layout(make<GBoxLayout>(Orientation::Vertical));
     widget->layout()->set_spacing(0);
 
+    StringBuilder path;
+    path.append(getenv("PATH"));
+    if (path.length())
+        path.append(":");
+    path.append("/bin:/usr/bin:/usr/local/bin");
+    setenv("PATH", path.to_string().characters(), true);
+
     if (!make_is_available())
         GMessageBox::show("The 'make' command is not available. You probably want to install the binutils, gcc, and make ports from the root of the Serenity repository.", "Error", GMessageBox::Type::Error, GMessageBox::InputType::OK, g_window);