feat(menu): #76 slice 2 — Hibernate notifies on failure

Per the settled #76 UX call: keep the Power-menu Hibernate row
unconditional, but when hibernate fails (typically a swap=0 machine with
no disk swap), surface a notification pointing at the enable-hibernation
runbook instead of a silent no-op. On success `systemctl hibernate`
blocks until resume, so the notify only fires on a real failure.

Verification: V1 — homeConfigurations.nomarchy.activationPackage builds
(rebuilds nomarchy-menu; writeShellScriptBin runs bash -n). Control-flow
proved on the arm extracted from the built script: failing systemctl ->
notify fires, succeeding -> no notify. flake check --no-build green.
V2 hibernate->resume VM test + V3 laptop remain open (#76 slice 3).

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

modules/home/rofi.nix

@@ -252,7 +252,13 @@ let
           *Lock)      loginctl lock-session ;;
           *Logout)    hyprctl dispatch exit ;;
           *Suspend)   systemctl suspend ;;
-          *Hibernate) systemctl hibernate ;;
+          *Hibernate)
+            # zram can't hold a hibernate image; a machine installed with
+            # swap=0 has no disk swap. Attempt, and if logind rejects it,
+            # say why instead of a silent no-op. On success this blocks
+            # until resume, so the notify only fires on a real failure.
+            systemctl hibernate 2>/dev/null \
+              || notify-send "Hibernate" "Couldn't hibernate — likely no swap is configured. See docs/MIGRATION.md → Enabling hibernation." ;;
           *Reboot)    systemctl reboot ;;
           *Shutdown)  systemctl poweroff ;;
         esac ;;