LilyPond text spanner text with \halign

Text spanner text can align directly in markup. Use \halign

\new Staff {
   c'4
   \override TextSpanner #'bound-details #'left #'stencil-align-dir-y =
      #center
   \override TextSpanner #'bound-details #'left #'text =
      \markup { \halign #-1 \italic "vif" \hspace #2 }
   c'4 \startTextSpan
   c'4
   c'4 \stopTextSpan
}


\new Staff {
   c'4
   \override TextSpanner #'bound-details #'left #'stencil-align-dir-y =
      #center
   \override TextSpanner #'bound-details #'left #'text =
      \markup { \halign #0 \italic "vif" \hspace #2 }
   c'4 \startTextSpan
   c'4
   c'4 \stopTextSpan
}


\new Staff {
   c'4
   \override TextSpanner #'bound-details #'left #'stencil-align-dir-y =
      #center
   \override TextSpanner #'bound-details #'left #'text =
      \markup { \halign #1 \italic "vif" \hspace #2 }
   c'4 \startTextSpan
   c'4
   c'4 \stopTextSpan
}

The reference point is, in each case, the left edge of the attachment note.