- Was Ruku evolved by the direct order from Allah [ie in the time of the Prophet (Sm)]?
- When was it added to Quran?
- Who was/were the pioneer?
- Why was it added?
A ruku'in the quran is a small section that is grouped up based on the meaning of the ayat that are grouped.
An example of a ruku would be the first 7 ayat of surat baqarah.
The origin of this did not begin during the time of the prophet, in fact it is not even recognized worldwide, hence the reason for people misunderstanding your question.
Organizing the quran in ruku' started in south asia, when people began disecting the quran into sections to prepare for taraweeh in ramadan. they seperated it into 540 section to read in each raka' of the month, hence the name "ruku'." this beame a guide for people leading prayer to know how many ayat to say, instead of just guessing.
it is not known when exactly this tradition started, but it still used today by color coding certain quran's sections.