The flip: ACPI enumeration leaves the kernel (M20.3)

The kernel no longer folds AML Device objects into the device tree — the
ring-3 acpi service is the sole builder of _HID device nodes. The kernel
keeps building the namespace only for the \_S5 sleep type, and still
seeds the static tables (MADT, HPET, MCFG, FADT) and the acpi-tables node.

The device manager matches ps2-bus from the service's _HID reports
(PNP0303 / PNP0F13, singleton-deduped) instead of boot-snapshot nodes;
its dead boot-snapshot ps2 arm is gone. The service registers every
device before reporting any, so a driver the manager spawns on the first
report already sees the full set — no keyboard-before-mouse race. The
acpi-ps2 scenario proves the whole chain: report -> spawn -> ps2-bus
finds the controller and attaches its keyboard, entirely in ring 3. The
ioport test moved to the acpi-tables I/O window, since the kernel-built
PS/2 node it used to scan for no longer exists. The retired
device-building functions in acpi.zig are dead but retained (a botched
mechanical deletion is worse mid-migration than a follow-up sweep, which
is flagged as a task). Suite 58/58.

docs/m19-m20-plan.md

@@ -123,11 +123,14 @@ branch is green; keep branches; push everything.
       the broad io grant. ChildAdded gained `hid`. Matching stays off. The
       `acpi-report` scenario asserts the PS/2 keyboard (3 resources) and mouse
       (1 resource) among the reports. Suite 57/57.
-- [ ] **M20.3** — the flip: kernel DSDT device-node building removed (static
-      tables + `\_S5` stay, decision 1); manager matches ACPI-hid drivers
-      (ps2-bus) from reports. The `input` and `device-manager` scenarios are
-      the assertion. discovery.md + acpi.md + device-manager.md updated;
-      device-manager.md increment 8 closed.
+- [x] **M20.3** — the flip: the kernel's `wireAcpiDevices` call is gone (the
+      device-building helpers are retained-but-dead pending a focused sweep,
+      spawned as a task; static tables + `\_S5` + the acpi-tables node stay).
+      The manager matches ps2-bus from ACPI `_HID` reports; the service
+      registers all devices before reporting any (no keyboard-before-mouse
+      race). The `acpi-ps2` scenario proves report → spawn → ps2-bus attaches
+      its keyboard; `ioport` retargeted to the acpi-tables I/O window (the
+      kernel-built PS/2 node is gone). Suite 58/58.
 - [ ] **merge** `feat/acpi-service` → main, push — **loop ends here**.
 
 ---