polish(nightlight): geo-mode tooltip says it follows the location

"Warm on schedule" was wrong in geo mode — the schedule is computed
from lat/long. Tooltip now reads "follows your location" when geo is
active.

Verification: V1 — rode the same flake check + template-home build as
the exit-node commit.

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

modules/home/nightlight.nix

@@ -54,7 +54,7 @@ let
         # Waybar (polls every 3s): moon while running; print nothing otherwise so
         # the module self-hides — enable / re-enable from the System menu.
         systemctl --user is-active --quiet "$unit" \
-          && printf '{"text":"󰖔","tooltip":"Night light on — warm on schedule (click to disable)","class":"on"}\n'
+          && printf '{"text":"󰖔","tooltip":"Night light on — ${if geo then "follows your location" else "warm on schedule"} (click to disable)","class":"on"}\n'
         exit 0 ;;
       on)
         if installed; then write_on true; start; else install_feature; start; fi ;;