Avira,
The Ramban is quite clear. I don’t need an online presentation to read it:
כי ידיעת השם שהיא השגחתו בעולם השפל היא לשמור הכללים וגם בני האדם מונחים בו למקרים עד בא עת פקודתם אבל בחסידיו ישום אליו לבו לדעת אותו בפרט להיות שמירתו דבקה בו תמיד לא תפרד הידיעה והזכירה ממנו כלל כטעם לא יגרע מצדיק עיניו (איוב לו ז) ובאו מזה פסוקים רבים כדכתיב (תהלים לג יח) הנה עין ה’ אל יראיו וזולת זה
There are many other Rishonim that discuss the issue also (I don’t remember them off-hand). I understand that many interpret the Ramban, Rambam, and others to mean differently than what they appear to say. But the Netziv and Rabbi Tendler are not meshubad to such an intepretation.
Where do Chazal say that a person doesn’t stub their toe without it being announced min hashomayim?
But nothing I wrote, nor the Rambam and Ramban wrote, contradict the statement: “Everyone agrees that nothing happens without it being caused, whether directly or indirectly, by Hashem, as there is no power besides him, no reality besides him either.”
Of course, you statement is correct. But the key is the directly vs. indirectly. If Hashem sets up and sustains a world that operates according to certain rules and those rules cause an event to occur, Hashem has caused that event, indirectly. But that event may not reflect any judgment that person(s) effected specifically deserved that outcome.