What is the ruling on the money my friend took, which represents 10% of my profits, in exchange for monitoring the workflow and offering advice to the company owner, knowing that he is a capital partner and I did not agree to this deduction?

It is permissible for both physical effort and capital, or capital and two bodies, to be combined, with the profit distributed between them according to their agreement. There is no objection to your friend having a share of the profit if he performs work for the benefit of the company, provided there is a prior agreement on this, and that it applies to all the capital, not just the share of some partners. Your friend deducting 10% from your share for himself is not his right unless there was a prior agreement at the time of establishing the company, and it must apply to all the capital, not just your share alone.