Add OS settings panels for updates, printing, VPN, and related surfaces

Typed commands only: pacman/bakery/fwupd compose on Updates, CUPS/nmcli,
hyprsunset, fcitx5, MIME defaults, bakery track, restic (backup.toml 0600),
curated optional software, and an NVIDIA offer card gated on the probe file.

frontend/src/lib/views/NightLight.svelte

@@ -0,0 +1,145 @@
+<script lang="ts">
+	import { onMount } from "svelte";
+	import { invoke } from "@tauri-apps/api/core";
+	import { runStreamed } from "$lib/streaming";
+	import ViewScaffold from "$lib/components/ViewScaffold.svelte";
+	import Group from "$lib/components/Group.svelte";
+	import Hint from "$lib/components/Hint.svelte";
+	import NumberField from "$lib/components/NumberField.svelte";
+	import LogView from "$lib/components/LogView.svelte";
+
+	interface NightlightStatus {
+		installed: boolean;
+		running: boolean;
+		enabled: boolean;
+		temperature: number;
+		error: string | null;
+	}
+
+	let st = $state<NightlightStatus | null>(null);
+	let log = $state<string[]>([]);
+	let busy = $state(false);
+	let message = $state("");
+
+	async function refresh() {
+		st = await invoke<NightlightStatus>("get_nightlight");
+	}
+
+	onMount(refresh);
+
+	async function apply(enabled: boolean) {
+		if (!st) return;
+		message = "";
+		try {
+			st = await invoke<NightlightStatus>("set_nightlight", {
+				enabled,
+				temperature: st.temperature,
+			});
+			if (st.error) message = st.error;
+		} catch (e) {
+			message = `${e}`;
+		}
+	}
+
+	async function install() {
+		log = [];
+		busy = true;
+		await runStreamed("pacman_install", { packages: ["hyprsunset"] }, (line) => {
+			log = [...log, line];
+		});
+		busy = false;
+		await refresh();
+	}
+</script>
+
+<ViewScaffold title="Night light">
+	<Group
+		title="Hyprland twilight"
+		hint="hyprsunset owns the compositor color filter. hyprctl hyprsunset talks to its socket — the binary has to be installed and running."
+	>
+		{#if !st}
+			<Hint text="Loading…" />
+		{:else if !st.installed}
+			<Hint text="hyprsunset is not installed. Night light cannot run without it." />
+			<button class="primary" disabled={busy} onclick={install}>Install hyprsunset</button>
+		{:else}
+			<div class="row-switch">
+				<span>Night light</span>
+				<button
+					class="switch"
+					class:on={st.enabled}
+					role="switch"
+					aria-checked={st.enabled}
+					aria-label="Night light"
+					onclick={() => apply(!st!.enabled)}
+				>
+					<span class="knob"></span>
+				</button>
+			</div>
+			<NumberField label="Temperature (K)" bind:value={st.temperature} min={2000} max={6500} step={100} />
+			<button disabled={!st.enabled} onclick={() => apply(true)}>Apply temperature</button>
+			<Hint text={st.running ? "hyprsunset is running." : "hyprsunset will start when you enable night light."} />
+		{/if}
+		{#if message}<Hint text={message} />{/if}
+	</Group>
+	<LogView lines={log} />
+</ViewScaffold>
+
+<style>
+	.row-switch {
+		display: flex;
+		align-items: center;
+		justify-content: space-between;
+		background-color: var(--surface);
+		border-radius: var(--radius-primary, 8px);
+		padding: var(--space-md, 12px) var(--space-lg, 16px);
+		margin-bottom: var(--space-sm, 8px);
+	}
+
+	.switch {
+		width: 40px;
+		height: 22px;
+		flex-shrink: 0;
+		border-radius: 999px;
+		border: none;
+		background-color: var(--overlay);
+		padding: 2px;
+		cursor: pointer;
+		display: flex;
+		align-items: center;
+	}
+
+	.switch.on {
+		background-color: var(--accent);
+		justify-content: flex-end;
+	}
+
+	.knob {
+		width: 18px;
+		height: 18px;
+		border-radius: 50%;
+		background-color: var(--on-surface);
+		display: block;
+	}
+
+	button {
+		background-color: var(--surface);
+		color: var(--on-surface);
+		border: none;
+		border-radius: var(--radius-primary, 8px);
+		padding: var(--space-xs, 4px) var(--space-md, 12px);
+		cursor: pointer;
+		align-self: flex-start;
+		margin-top: var(--space-sm, 8px);
+	}
+
+	button.primary {
+		background-color: var(--accent);
+		color: var(--on-accent);
+	}
+
+	button:disabled {
+		opacity: 0.5;
+		cursor: default;
+	}
+</style>