Idea on terraforming Mars

Mars needs a strong magnetic field.
Thats what sustain the atmosphere.
Since Mars is geologically inert, burying strong perm-magnets all over the place would provide an artificial magnetic field on the surface.
And solar wind can be redirected.
https://www.extremetech.com/extreme/245369-nasa-proposes-building-artificial-magnetic-field-restore-mars-atmosphere

Now how to create the atmosphere and water cycle:
Water:
Obviously transporting water from earth is both costly and denies us resources.
This will require crashing water-rich comets into Mars or mining martian rocks to convert to water.
Oxygen:
Steal it from Venus CO2 rich-atmosphere and convert to liquid form to transport - or as above refining it from rocks.
Adding CO2 will allow plants(algae) to enrich the atmosphere with oxygen and kickstart the ecosystem.
May also help terraforming Venus.

>>2
Build factories on mars specifically to produce huge magnets using the mined minerals, then bury them in a pattern of mutually supporting fields to cover the entire surface. Mark sites of magnets for maintaince and replacement.
Add magnetic strength monitors at each section of magnetic grid.