fix(ui): #139 sheets size themselves; #141 waybar clicks stop reading the env

#139 — calcurse/doctor floated full-screen. Two faults stacked, which is
why it looked like the float rules were dead:
  1. Hyprland 0.55.4 silently ignores percentage `size` rules. Matrix on
     hardware (both orders, kitty memory off): `size 60% 65%` never
     applies, `size 1536 936` applies either way, configerrors empty both
     times. Rule order was a red herring.
  2. Kitty defaults to remember_window_size=yes and replays the last OS
     window's size into every float — so after a tiled terminal, a sheet
     opens maximized. This is the Ghostty regression: Ghostty had no such
     memory, so fault 1 stayed invisible until #95.

Fix: remember_window_size=no (floats must be deterministic) and the sheets
ask for their own size — term-sheet.nix reads the focused monitor and
hands kitty the px, because px in a rule cannot mean "a fraction of *this*
screen" and one pair cannot serve 2560x1440 and the 1366x768 Acer (#131).
Those windows keep float/center and deliberately carry no size rule.

#141 — the updates click did nothing: whole-swaps hand-wrote
`sh -c '$TERMINAL …'` and Waybar has no TERMINAL (home.sessionVariables →
login shells only; the bar is spawned by Hyprland). Fixed at the root:
`nomarchy-updates upgrade-window` opens its own window, so all five call
sites name one env-free command and a theme file stops having an opinion
about terminals. checks.waybar-swap-env guards the class.

Bernardo asked mid-task for the update window to float — it is now the
third caller of the sheet helper (com.nomarchy.updates, 45%x50%).

V3 on the dev box: calendar 1536x936, doctor 1408x1008, updates 1152x720
— exactly the intended fractions, floating and centred; #141 driven under
`env -i` with no TERMINAL, matching Waybar's real environment; the guard
proven by reintroducing the bug. Acer V3 queued.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

modules/home/updates.nix

@@ -14,6 +14,7 @@
 
 let
   cfg = config.nomarchy.updates;
+  termSheet = import ./term-sheet.nix { inherit pkgs; };
 
   nomarchy-updates = pkgs.writeShellScriptBin "nomarchy-updates" ''
     set -u
@@ -113,7 +114,23 @@ let
         fi
         "$0" check
         echo "Done — press enter."; read -r _ || true ;;
-      *) echo "usage: nomarchy-updates [check|status|upgrade]" >&2; exit 64 ;;
+      upgrade-window)
+        # The Waybar click target. `upgrade` prompts, so it needs a terminal —
+        # and the bar has none: it is spawned by Hyprland, whose environment has
+        # no $TERMINAL (that is a home.sessionVariables entry, so only login
+        # shells see it). A whole-swap's hand-written on-click that reached for
+        # $TERMINAL expanded to nothing and the click silently did nothing
+        # (#141). Opening our own window is the fix that cannot rot: every
+        # caller — generated module and whole-swap alike — names one env-free
+        # command, and a theme file stops having an opinion about terminals.
+        #
+        # A classed sheet like the calendar and doctor: a short y/N flow has no
+        # business taking the whole screen, and the class is what hyprland.nix
+        # floats it by. Smaller than either (45%x50%) — this is a prompt, not a
+        # document.
+        exec ${termSheet}/bin/nomarchy-term-sheet com.nomarchy.updates 45 50 \
+          "$0" upgrade ;;
+      *) echo "usage: nomarchy-updates [check|status|upgrade|upgrade-window]" >&2; exit 64 ;;
     esac
   '';
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