docs: README, plan, guides and the site describe what is built now

README: rewritten around what runs (Linux software, Xorg, apk, Linux's drivers), the honest gaps, measured numbers.
plan/: 1.0.md is the finish line, where each clause of the acceptance test stands, and the register (one failing
clause: a root that survives a reboot); built plans (foundations, hybrid, alpine, xorg) and the decided-against one
(wayland) are gone, their content lives in architecture/; roadmap.md is only what is still open.
guides: building/layout/testing/adding-a-driver (Linux code may be used). history: four entries (ls -lR, TLB
shootdowns, MDIO 0x02460246, netlink MSG_TRUNC). Website: cards, stack, download page, docs index.
Code comments that pointed at deleted plan docs point at the architecture docs.

Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01EVRhxi9zpdW2uDUN4FVcao

docs/architecture/ldls.md

@@ -330,7 +330,7 @@ one flag and hands over all 65536 ports, including the interrupt controller,
 the timer and the disk; the TSS I/O permission bitmap is per port. A foreign
 driver already has DMA with no IOMMU, and the answer to "this is not a security
 boundary" is not to move it further — so it is the bitmap, at 8 KB per CPU of
-resident memory. See [../../include/ioperm.h](../../include/ioperm.h).
+resident memory. See [../../include/arch/ioperm.h](../../include/arch/ioperm.h).
 
 Writing it found a latent hole. The TSS's I/O map base is at offset 102 and the
 old code wrote offset 64; the field it meant to set stayed 0, and a base of 0