Chapter title format is too wide

Question

I have the problem that my chapter title is too wide, because it has the same width like the line below. How can I change the width from the title? For example, when you uncomment the \geometry{...} lines, it works but not much enough. AND why are the two lines not directly among each other (e.g. the two left "T"'s)?

MWE:

\documentclass[paper=a4, fontsize=12pt]{scrreprt}

\usepackage{classicthesis}

\usepackage{geometry}
\geometry{
    a4paper,
    top=3cm,
    bottom=3cm,
    left=3cm,
    right=3cm
}

\titleformat{\chapter}[display]%
{\relax}{\vspace*{-3\baselineskip}\makebox[\linewidth][r]{\color{halfgray}\chapterNumber\thechapter}}{10pt}%
{\raggedright\spacedallcaps}[\normalsize\vspace*{.8\baselineskip}\titlerule]%


\begin{document}
    \chapter{Test title Test title Test title Test title Test title Test title }
\end{document}

Title:

I wan't this, but with variable/more space between chapter title and right end (result by uncomment the geometry, but that is not the solution because I need it)