Backgrounds load with no saved theme choice, 2026-10-12

Tasks 19.1 and 19.2 of change the-shell-swaps-themes-without-a-python-stall.

The source is master 1cc7ebe1, in worktree /home/jadams/tmp/k230-bg-fix, branch fix/backgrounds-without-saved-theme. Times are UTC.

Evidence classes:

coherent-installer serial checks;
one software-injected tap over SSH;
one native grim capture.

No finger or camera observation is claimed.

Identity	Value
Bundle	`/nix/store/8h1986l9ywg5g73mjjssm5zgg9iy6xcs-k230-coherent-shell-boot-files`
System	`/nix/store/cwfx0amrcgxb0ni7pdpq2ij4rr8yz7bh-nixos-system-nixos-26.11.20260919.20b1ddd`
Rust shell ELF	`/nix/store/k2z9z61khs97ks3m2sm2ymhrisk13h5m-k230-shell-rust-riscv64-unknown-linux-gnu-0.1.0/bin/k230-shell-rust`
Kernel, `Image`, `initrd.uimg`	unchanged from the baseline
Baseline	combined install `zvxmd93g…` (../combined-install-2026-10-12/)

Install

The build ran with flock /tmp/k230-nix-build.lock nix build .#kernelMainlineDrmShellBootFiles --out-link ~/.local/state/tdisplay-k230/retained-builds/bg-fix-2026-10-12/candidate --print-out-paths --max-jobs 1 --cores 4 and exited 0.

The coherent installer then ran with the same recipes as the combined install. Only the paths and the baseline differ (see the *-used.py files). Every step passed:

Preflight: boot 9de0e538-…, 07:43:53 (preflight.json).
Stage: (stage.log, transfer.json, staged-state.json, host-inspection.json).
Candidate boot: (candidate-boot.json). The runtime check ran on boot 8909583b-… at 07:49:36 (candidate-runtime.json).
Qualification: (deployment-authorization.json).
Install and ordinary autoboot: (ordinary-boot.json). The runtime check ran on boot a563b9fb-… at 07:52:48 (ordinary-runtime.json). The current system and profile are both cwfx0amr…, and the four shell services are active.

Task 19.2 check

open-themes-used.py ran as root over SSH, on the ordinary boot a563b9fb-…. It performs these steps:

Starts a temporary virtual K230 injected touchscreen (evemu-device).
Runs k230-shell-rust --surface settings as shell.
Taps Themes at (480, 130).
Waits 15 s.
Runs grim -s 0.5.
Prints k230-theme list’s active field.
Stops the device unit.

Results:

Saved choice: k230-theme list printed "active": {"generation": null, "id": null}, so the board still has no durable theme choice.
Picker: themes-without-saved-choice-native.png. The theme carousel is centred on catppuccin, labelled “Built in” rather than “Current theme”.
Backgrounds row: it shows Totoro, labelled “Current background on Home”, with neighbours to the right, instead of “Loading backgrounds”.

Before the fix, the same state left the row on “Loading backgrounds”. The board-session agent reproduced that twice (../board-session-2026-10-12/README.md).

This is one opening. The tap was software-injected, and no glass or finger view was taken.