Fix stale docs: grub cmdline now has resume params, swapfile back for hibernation

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

CLAUDE.md

@@ -63,7 +63,9 @@ scaling) and it's only the greeter — the actual logged-in Plasma/Wayland
 session correctly renews the modeset itself and comes up at full native
 `3200x1800` with 125% scaling, confirmed working. No kernel cmdline
 workarounds are needed — `/etc/default/grub`'s `GRUB_CMDLINE_LINUX_DEFAULT`
-is back to a clean `'splash'`.
+has no i915 params (as of 2026-09-28 it's `'splash resume=UUID=…
+resume_offset=…'`; the resume params are for hibernation, see
+`NEON-CUSTOMIZATIONS.md`).
 
 Confirmed reliable across multiple clean `sudo systemctl poweroff` /
 power-on cycles. The GRUB default entry (index 0, `GRUB_DEFAULT=0`) auto-

NEON-CUSTOMIZATIONS.md

@@ -62,7 +62,9 @@ named in the black-screen notes in `CLAUDE.md`. Old 7.x kernels
 `/etc/default/grub` (edited by hand several times; both `matt` and root
 history show `nano /etc/default/grub` + `update-grub`): `GRUB_DEFAULT=0`,
 `GRUB_TIMEOUT=5`, `GRUB_TIMEOUT_STYLE=menu`,
-`GRUB_CMDLINE_LINUX_DEFAULT='splash'` (see `setup-i915-kernel7-fix.sh`).
+`GRUB_CMDLINE_LINUX_DEFAULT='splash resume=UUID=3af45daa-b8c2-4053-9574-a958e0c3ea68
+resume_offset=17674240'` (the `resume` params were added 2026-09-28 for
+hibernation, see below; see also `setup-i915-kernel7-fix.sh`).
 
 ## Storage / wear on the microSD root
 

ZRAM.md

@@ -6,18 +6,19 @@ in RAM. That suits this machine: 15GiB RAM, and neon's root lives on a
 slow microSD card in the built-in slot (`sda`) that you don't want to swap to or wear
 out.
 
-## Current state (2026-09-27)
+## Current state (2026-09-28)
 
 ```
-$ zramctl
-NAME       ALGORITHM DISKSIZE DATA COMPR TOTAL STREAMS MOUNTPOINT
-/dev/zram0 zstd            8G   4K   59B   20K         [SWAP]
 $ swapon --show
 NAME       TYPE      SIZE   USED PRIO
-/dev/zram0 partition   8G   0B  100
+/dev/zram0 partition   8G 582.5M  100
+/swapfile  file       16G     0B   10
 ```
 
-The zram device is the only swap. zswap is off
+zram (priority 100) takes all everyday swapping. The 16GB `/swapfile`
+(priority 10) is there for the hibernation image (see
+"Suspend-then-hibernate" in `NEON-CUSTOMIZATIONS.md`). It only gets
+ordinary swap pages if zram fills up. zswap is off
 (`/sys/module/zswap/parameters/enabled` = `N`), and there's nothing
 zram-related on the kernel command line.
 
@@ -82,8 +83,8 @@ SIZE=8192
 PRIORITY=100
 EOF
 sudo systemctl enable --now zramswap
-# comment out any /swapfile line in /etc/fstab, then:
-sudo swapoff /swapfile
+# drop any old swapfile from /etc/fstab (a hibernation swapfile is set
+# up separately, see NEON-CUSTOMIZATIONS.md)
 # persist swappiness
 echo 'vm.swappiness=100' | sudo tee /etc/sysctl.d/99-zram.conf && sudo sysctl --system
 ```