Keyboard lights, TLB shootdowns, battery in sysfs, /proc/pid/maps

Caps, Num and Scroll Lock now light their LEDs on PS/2 and USB keyboards,
share one state between keyboards, and stop toggling on key repeat. X sets
them through evdev writes while it holds the keyboard.

Unmapping memory in a process with threads on other CPUs now flushes their
TLBs with an IPI. Without it a freed page stayed reachable through stale
translations, which corrupted Epiphany's heap on SMP.

ACPI batteries and AC adapters appear under /sys/class/power_supply.
/proc/<pid>/maps lists file mappings, and a process killed by a fault
names the file and offset it died in. r8169 gets a 256-entry RX ring.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01S1giNvrHTrPMPw7V6x1kQ4

Makefile

@@ -119,7 +119,7 @@ KERN_ZSTD += $(BUILD)/kernel/scff/scff.o
 KERN_GMMOS = $(addprefix $(BUILD)/kernel/gmmos/, gmmos.o hidkeys.o ps2.o i2c.o xhci.o)
 
 KERN_PROC = $(addprefix $(BUILD)/kernel/proc/, \
-              proc.o)
+              proc.o mapname.o)
 
 KERN_SYS  = $(addprefix $(BUILD)/kernel/sys/, \
               syscall.o sys_proc.o sys_fs.o sys_mem.o sys_net.o \