Staircase shifted by 10 cm, options?

More space at the bottom would be the goal. At the top, I am not opposed to "I will do my very best." No, seriously... At the top, I don’t care how wide the first step is, as long as it matches with the other flooring.

The first question would be why this is only now being noticed and criticized when there are obviously pictures showing the recognizable defect without screed.

Relocating it could be interesting. Below, it might be possible to mount an angle in the hole on which the lower holder could then be mounted; unfortunately, the attachment at the top is not visible, and I cannot conclusively say whether something like this is fundamentally possible, as mentioned, just an idea for now.

Alternatively, if it is about the created tripping hazard, have the wall built up/extended by 10cm and live with the 95cm passageway as annoying as it is.

So I see a solvable problem here. Have the Estich below removed. Loosen the stairs, shorten at the top and weld on the corresponding bracket, extend the stairs accordingly at the bottom. Since it is steel and not wood, the problem should be relatively easy to solve. Whether the stairs need to be dismantled for this or adjusted in the installed state with appropriate lifting equipment, the stair builder has to decide. Who then bears the costs is the other question.

So I see a solvable problem here. Have the screed removed at the bottom. Loosen the staircase, shorten at the top
and weld an appropriate bracket, extend the staircase accordingly at the bottom.
Since it is steel and not wood, the problem should be relatively easy to solve.
Whether the staircase has to be removed for this or adjusted in its installed condition with appropriate lifting equipment
must be decided by the staircase builder.
Who will bear the costs is another question.

That was also my first thought on changing the staircase attachment. Loosen the attachment at the bottom, push the staircase backwards, attach the staircase at the bottom with "lying" square tubes instead of the currently standing ones at the old support points. Or screw the stringer end-wise to the base plate. There are possibilities.
However, one can see a lateral attachment of the stringer to the wall at step 5 or 6. This will make relocating the staircase difficult.

However, at level 5 or 6, a lateral attachment of the stair stringer to the wall can be seen. This will make relocating the staircase difficult.

If there is "only a square tube in the wall, you break open the 10 cm behind it, move the staircase, and mortar it again. Since this topic is obviously very important to the OP, a solution will be found.

The staircase is anchored in the wall at two points. Unfortunately, I do not know exactly how this is executed. But knowing that it is feasible is already an important point for me. The CM should think about the costs ;-)