acpi: stop parsing AML in the kernel; power management is userspace's

Kernel discovery interpreted the whole DSDT/SSDTs (~0.5 MB -> ~9700 nodes) solely to extract the _S5 sleep type for a kernel-side soft-off — ~1-2s of work on the single-core, pre-scheduler critical path, with nothing to overlap it. The ring-3 acpi service already parses the same blobs and owns S5 end-to-end (reads pm1a_cnt from the FADT, writes SLP_TYP itself; orderly-shutdown tests it). So drop the kernel parse entirely.

- all *static*-table parsing stays (MADT/HPET/FADT/MCFG): CPUs, timers, PCIe, and the power register map are still detected from ACPI, not legacy/compat addresses (timer still calibrates via HPET/PM-timer/CPUID, PIT only as last resort)
- kernel keeps reboot (FADT reset register + legacy fallbacks — no AML); soft-off is userspace-only now
- removed PowerInformation.s5/s3, the kernel AML namespace, aml_stats, amlDeviceCount, and the aml import; power.shutdown/enable/sleepS3 gone
- tests: poweroff case retired (S5 covered by orderly-shutdown); discovery drops its S5/AML checks; acpi-parse self-verifies against a device-count floor since there's no kernel count to match

system/services/acpi/acpi.zig

@@ -103,9 +103,11 @@ fn findTablesNode(buffer: []device.DeviceDescriptor) ?device.DeviceDescriptor {
 }
 
 pub fn main(init: runtime.process.Init) void {
-    // When the acpi-parse scenario spawns this directly, argv[1] is the kernel's
-    // own device count to self-verify against — deterministic, no log-scraping.
-    const expected: ?usize = if (init.arguments.get(1)) |a| (std.fmt.parseInt(usize, a, 10) catch null) else null;
+    // When the acpi-parse scenario spawns this directly, argv[1] is a device-count
+    // *floor* to self-verify against. The kernel no longer parses AML, so there is
+    // no exact count to match — proving the ring-3 parse found at least a floor of
+    // devices is the check. Deterministic, no log-scraping.
+    const floor: ?usize = if (init.arguments.get(1)) |a| (std.fmt.parseInt(usize, a, 10) catch null) else null;
 
     const buffer = runtime.allocator().alloc(device.DeviceDescriptor, 64) catch {
         _ = runtime.system.write("/system/services/acpi: out of memory\n");
@@ -162,11 +164,11 @@ pub fn main(init: runtime.process.Init) void {
     var namespace = result.namespace;
     const devices = aml.deviceCount(&namespace);
     writeLine("/system/services/acpi: parsed {d} AML blob(s), {d} namespace devices\n", .{ block_count, devices });
-    if (expected) |want| {
-        if (devices == want) {
+    if (floor) |minimum| {
+        if (devices >= minimum) {
             _ = runtime.system.write("acpi-parse: ok\n");
         } else {
-            writeLine("acpi-parse: mismatch (ring-3 {d} vs kernel {d})\n", .{ devices, want });
+            writeLine("acpi-parse: too few (ring-3 {d} < floor {d})\n", .{ devices, minimum });
         }
         // Self-verify mode is standalone (no manager); stop before reporting.
         while (true) runtime.system.sleep(1000);