I am not aware of any international treaties which sanction the use of force against a non-signatory nation except for those circumstances under which one of the signatory nations is first attacked by a non-signatory nation (e.g. collective defense agreements such as NATO). Your counterexample of the Israeli airstrike on the Osirak reactor is not a precedent as it was not a lawful use of force according to international law and was not sanctioned by any treaty. I agree that the Israeli government made the right decision in orchestrating the attack, but it is important to point out the differences between that and what you are suggesting.
Ultimately, to quibble about whether your suggestion is an “act of violence” or not misses the point. What you suggest would be an unprecedented sanctioning of force. I believe the introduction of such an agreement would be very incendiary and would offer a bad precedent. Note that no such agreement was signed in order to prevent nuclear proliferation. Many experts were very worried that nuclear weapons would proliferate much further than they ultimately did. Sometimes the use of force was used, but always with a lighter hand than “let’s sign a treaty to bomb anyone we think has a reactor.”
My future profits aren’t very relevant if I’m dead, but I might still care about it even if I’m super rich. Sure, my marginal utility will be very low, but on the other hand the profit from my investments will be very large. Even if everyone is stupendously rich by today’s terms, there might be a tangible difference between having a trillion dollars in your bank account and having a quadrillion dollars in your bank account. Maybe I want my own galaxy in which I alone have the rights to build Dyson spheres and that is out of the price range of your average joe with a trillion-dollar net wealth. Maybe (and this might be more salient to your typical investor who isn’t actively thinking about far out sci-fi scenarios) I want the prestige, political control, etc, that come with being wealthy compared to everyone else.
If future benefits exist for being even richer after TAI, interest rates could rise due to inductive reasoning even before consumers begin adjusting their savings rates in response to TAI. If I know that consumers will adjust their savings rate one day before TAI (assuming a deterministic timeline where TAI occurs in one discontinuous jump and very unrealistic timescales for consumers changing their savings rate for simplicity’s sake), then I should place a bet on the interest rate rising (e.g. shorting government bonds) two days before TAI. If enough investors take this action, then interest rates will rise two days before TAI. Knowing this, I should short government bonds three days before TAI, etc… Similar to how if the government promises to print a lot of money in one month, then inflation will begin to rise immediately.