It is not a coup because he became president by force. It is a coup because he is consolidating power. (The president is not supposed to be all powerful.)
[1] https://dictionary.cambridge.org/dictionary/english/coup
The violent part and the army part seems to be optional
1) Remove all opposition for DOJ (already done)
2) Pass executive orders that should require congressional approval (doing)
3) Illegally seize control of the treasury (doing)
4) Broadly dismantle key government services (doing)
5) Watch politicians say, "you can't do that!" with no recourse (doing)
Continually take control more and more broadly until you have absolute power.
I'm not going to stop you calling it a coup, but your opponents will just smile and say "not true" and they would be right.
Musk is committing illegal acts, over a weekend, in taking government power by, at minimum, not being appointed and confirmed. This is a coup by the definition YOU provided.
I wonder if Trump and Vance in 2029 can somehow pull the Putin/Medvedev switch, where the real leader takes a nominal secondary position until they can fix the constitutional issue.
