Modularize drivers and overhaul terminal/account flows
* Add a staged kernel driver manager and migrate x86 + core drivers (ATA/AHCI/xHCI/USB MSC/framebuffer/serial/PS2) into explicit load/unload registrations with busy checks and dependency-safe teardown.
* Rework storage/devfs/USB plumbing for dynamic register/unregister paths (device/hcd/class detach handling, disk busy detection, late /dev publishing, and rootfs mount flow cleanup).
* Unify console/term rendering around shared ANSI/UTF-8/cell/cursor/glyph helpers, add PSF Unicode map support, and switch default fonts/cursor assets to ter-116n-based configuration.
* Add supplementary group support end-to-end (/proc/*/groups, scheduler creds, libc getgroups/setgroups) and wire it into login/su/id/groups plus updated passwd/group/shadow defaults.
* Add new less/su user commands and tighten shell/ls/runtime build tooling (pipeline/wait fixes, escape-key polling, metadata-aware rootfs image staging, stripped user bins, and richer QEMU USB/KVM presets).