feat(nightlight): geo mode — lat/long-computed sunset via wlsunset

Set BOTH nomarchy.nightlight.latitude/.longitude and the night light
switches backing unit: wlsunset computes sunrise/sunset from the
location daily (the fixed .sunrise/.sunset are ignored;
.temperature feeds the night temp). Everything user-facing is
unchanged — same nomarchy-nightlight toggle script, Waybar moon, and
live-state ExecCondition gate; the unit name is a single let-binding
so all three follow together. Declarative-only on purpose: coordinates
are machine config like the keyboard layout, so home.nix (commented
template example), not a menu writer.

checks.nightlight-geo guards the wiring at pure eval: rendered
wlsunset ExecStart carries the coords + night temperature, the
ExecCondition gate landed on the swapped unit, hyprsunset stays off in
geo mode.

Verification: V1 — nix flake check --no-build exit 0 (evals the new
asserts + option-docs sync); built downstream-template-home (default
hyprsunset path unregressed). V3 pending: visible warm shift at the
location's night + instant toggle/off-persistence on the swapped unit
(HARDWARE-QUEUE § Any machine).

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

docs/ROADMAP.md

@@ -721,10 +721,16 @@ Design/decision records and a running log of shipped work (items marked
   outside the checkout** (Phase 1 night-light + Phase 2 the per-device
   keyboard-layout memory below are done — both now in the git-tracked state
   file; next target: opt-in auto-commit of the flake on each mutation, owned
-  files only). Remaining (optional): geo (lat/long) auto
-  sunset/sunrise (would mean wlsunset, which schedules by location). Pending an
-  on-machine check (first enable rebuilds + comes on; later toggles instant; off
-  persists across reboot via ExecCondition; stopping hyprsunset restores gamma).
+  files only). The on-machine check PASSed 2026-07-04 (enable/disable on
+  hardware). **Geo mode shipped 2026-07-11:** set BOTH
+  `nomarchy.nightlight.latitude`/`.longitude` and wlsunset replaces
+  hyprsunset — sunrise/sunset computed from the location daily, the fixed
+  times ignored; same toggle script, moon indicator, and live-state
+  `ExecCondition` gate (the backing unit name is a single let-binding).
+  Declarative-only on purpose (coords are hardware-independent machine
+  config, like the keyboard layout — no menu writer). Guarded by
+  `checks.nightlight-geo` (pure eval over the rendered units); the visible
+  warm shift is hardware-tier, queued.
 - ✓ **Automatic timezone (location-following clock):** `nomarchy.system.autoTimezone`
   (opt-in, off by default) — geoclue + `services.automatic-timezoned` drive
   `/etc/localtime` from your location, so travelling to another zone updates the