What is the ruling on lunch and dinner invitations extended by companies to different types of clients, distributing gifts to them, presenting sham price offers for government tenders, and purchasing supplies from a company affiliated with the institution after securing the project?

What has been mentioned cannot be judged as permissible or forbidden with a single ruling. If it is for the purpose of influencing decision-makers in companies and coveting their favoritism in what is impermissible, then it is a forbidden bribe. If that is not the intention, then there is no harm in it.

As for an official asking for two offers, one from your company and one from an affiliated company, if it is due to the unavailability of other options or the quality of the product, then there is no harm. However, if it is deception against his company for the sake of showing you favoritism, then it is impermissible to cooperate with him, due to the Almighty’s saying: "And do not cooperate in sin and aggression," and due to the Prophet's (PBUH) saying: "Whoever cheats us is not of us."