  Stars form from the gravitational collapse of turbulent, magnetized molecular
cloud cores. Our non-ideal MHD simulations reveal that the intrinsically
anisotropic magnetic resistance to gravity during the core collapse naturally
generates dense gravo-magneto-sheetlets within inner protostellar envelopes --
disrupted versions of classical sheet-like pseudodisks. They are embedded in a
magnetically dominant background, where less dense materials flow along the
local magnetic field lines and accumulate in the dense sheetlets. The
sheetlets, which feed the disk predominantly through its upper and lower
surfaces, are the primary channels for mass and angular momentum transfer from
the envelope to the disk. The protostellar disk inherits a small fraction (up
to 10\%) of the magnetic flux from the envelope, resulting in a disk-averaged
net vertical field strength of 1-10 mG and a somewhat stronger toroidal field,
potentially detectable through ALMA Zeeman observations. The inherited magnetic
field from the envelope plays a dominant role in disk angular momentum
evolution, enabling the formation of gravitationally stable disks in cases
where the disk field is relatively well-coupled to the gas. Its influence
remains significant even in marginally gravitationally unstable disks formed in
the more magnetically diffusive cases, removing angular momentum at a rate
comparable to or greater than that caused by spiral arms. The magnetically
driven disk evolution is consistent with the apparent scarcity of prominent
spirals capable of driving rapid accretion in deeply embedded protostellar
disks. The dense gravo-magneto-sheetlets observed in our simulations may
correspond to the ``accretion streamers" increasingly detected around
protostars.
