refactor(display): extract the shared display-transition + keyboard tools (#150)

The full nomarchy-display-transition (dock/undock/enable — logging, the
lid-inhibitor gate, restore_keyboards, the failure dump) and the
nomarchy-keyboard-layout helper it calls move out of hyprland.nix into
leaf files (modules/home/display-transition.nix, keyboard-tool.nix),
imported by both hyprland.nix and idle.nix.

This kills the lossy ~22-line mini idle.nix carried under the same binary
name to dodge a circular import. The hypridle wake path (after_sleep /
DPMS on-resume) now runs the real undock — restore_keyboards after a
reload and the evidence dump on enable-failure — instead of a bare
keyword+reload, and the two copies can no longer drift.

Behaviour on the hyprland side is unchanged: the built
nomarchy-display-transition and nomarchy-keyboard-layout have
byte-identical store paths on HEAD vs this change (verbatim extraction).

Verify: all four files parse; home activationPackage + system toplevel
build; checks.docking-ux green (bash -n + safety-feature greps on the
extracted scripts). The tools/monitor-fallback.nix dock harness is red on
main already (the #148 reload-mid-dock assertion — identical failure on
clean HEAD; filed BACKLOG #154), so it could not gate this. The idle
wake-path behaviour change (full undock, incl. dock-intent clearing) is
V3 pending: on-hardware suspend/resume + zero-output rescue queued in
HARDWARE-QUEUE.

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

modules/home/idle.nix

@@ -21,35 +21,23 @@ let
   '';
 
   # Absolute store paths for hypridle (thin PATH). Wake reuses the shared
-  # helper; a mini transition avoids a circular import on hyprland.nix.
+  # helper AND the full display-transition tool (#150): idle.nix used to
+  # carry a lossy mini copy to dodge a circular import on hyprland.nix, but
+  # both live in leaf files now, so the wake path gets the real undock —
+  # logging, the enable-failure dump, and restore_keyboards after a reload.
   displayWake =
     let
-      miniTransition = pkgs.writeShellScriptBin "nomarchy-display-transition" ''
-        set -u
-        case "''${1:-}" in
-          undock|enable)
-            internal="''${2:-}"
-            [ -n "$internal" ] || exit 64
-            hyprctl keyword monitor "$internal,preferred,auto,1" >/dev/null 2>&1 || true
-            if ! hyprctl monitors -j 2>/dev/null \
-                  | ${pkgs.jq}/bin/jq -e --arg m "$internal" 'any(.[]; .name == $m)' \
-                  >/dev/null 2>&1; then
-              hyprctl reload >/dev/null 2>&1 || true
-              sleep 0.5
-            fi
-            hyprctl keyword monitor "$internal,preferred,auto,1" >/dev/null 2>&1 || true
-            hyprctl dispatch dpms on >/dev/null 2>&1 || true
-            hyprctl monitors -j 2>/dev/null \
-              | ${pkgs.jq}/bin/jq -e --arg m "$internal" 'any(.[]; .name == $m)' \
-              >/dev/null 2>&1
-            ;;
-          *) exit 64 ;;
-        esac
-      '';
+      keyboardTool = import ./keyboard-tool.nix { inherit pkgs lib config; };
+      displayDumpTool =
+        (import ./display-tools.nix { inherit pkgs; }).displayDumpTool;
+      displayTransition = import ./display-transition.nix {
+        inherit pkgs keyboardTool displayDumpTool;
+        sync = lib.getExe config.nomarchy.package;
+      };
     in
     (import ./display-tools.nix {
       inherit pkgs;
-      displayTransition = miniTransition;
+      inherit displayTransition;
     }).displayWakeTool;
 in
 {