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>

agent/BACKLOG.md

@@ -175,24 +175,26 @@ If that count is zero over a few weeks post-linger, **close this unbuilt**. If i
 is not, the upstream issue has sat ten months on vaxerski's "that will cause a
 segfault no?" and a reproducer would be worth more than a local guard.
 
-### 150. Extract the display-transition tool — idle.nix carries a lossy copy under the same name
+### 154. `[watch]` `tools/monitor-fallback.nix` is red on `main` at the #148 reload-mid-dock assertion
 
-Found by the 2026-07-17 structural audit. `modules/home/idle.nix:23-53` defines
-`miniTransition`, a ~22-line `writeShellScriptBin` named
-**`nomarchy-display-transition`** — the same binary name as the real ~175-line
-tool in `modules/home/hyprland.nix:136-310` — implementing only
-`undock|enable`, with none of the full tool's safety: no logging, no
-lid-inhibitor gate, no `restore_keyboards`, no workspace moves, no
-failure dump. The comment says why: "a mini transition avoids a circular
-import on hyprland.nix". No PATH collision today (the mini is never installed;
-it is baked by store path into hypridle's wake tool via `display-tools.nix`),
-but nothing asserts the two stay behaviourally consistent, and this is the
-subsystem where #100/#142/#148 all lived. Pitch: extract the full tool into
-its own module file (e.g. `modules/home/display-transition.nix`) imported by
-both hyprland.nix and idle.nix, delete the mini, re-run the
-`tools/monitor-fallback.nix` harness + `checks.docking-ux` as the V2 gate.
-Cost: a focused refactor of safety-critical code — deliberately NOT done as
-hygiene drive-by; deserves its own iteration.
+Found while verifying #150 (2026-07-20): the dock/undock VM harness fails at
+the `enforce_dock_intent` step — after a lid-closed `hyprctl reload` it waits
+15s (generated `<string>:75`) for the watcher to re-disable `Virtual-1` and
+times out; the panel is never re-disabled and `action=re-dock` is never
+logged. **Confirmed pre-existing:** a clean-HEAD worktree run
+(fdf9790, before any #150 change) fails at the *identical* assertion, and the
+#150 refactor is proven inert here (the built `nomarchy-display-transition` /
+`nomarchy-keyboard-layout` have byte-identical store paths on HEAD vs the
+#150 branch). The `dock` transition itself succeeds (`result=ok`, both
+workspaces move, internal disabled) — only the post-reload re-dock invariant
+fails. Likely a harness/environment issue (the `enforce_dock_intent` tick
+depends on the watcher reading `settings.display.dockMode` from the in-flake
+state, which may not be writable in this NixOS-test sandbox) rather than a
+product regression — but it means the maintainer V2 dock harness is not a
+usable gate until re-greened. Do first: reproduce, then check whether
+`set_dock_intent` actually persists `dockMode=true` inside the VM (grep the
+run journal for `dock-intent=…state-write-failed`); if the state write is the
+gap, the fix is in the harness, not the watcher.
 
 ### 149. `[watch]` Waybar's exec-once workaround may be defending against nothing post-linger
 

agent/HARDWARE-QUEUE.md

@@ -534,6 +534,21 @@ Everything else below stays open; order is convenience, not a gate.
       bar, notifications, and clipboard history (SUPER+V) work. This is
       the V3 close for the stale `graphical-session.target` /
       `start-limit-hit` relogin breakage (BACKLOG #149 note).
+- [ ] **#150 hypridle wake path now uses the FULL undock** — after pulling
+      the #150 commit + `nomarchy-home`: the hyprland-side transition/keyboard
+      tools are byte-identical (proven by store-path equality), so only the
+      hypridle wake behaviour changed. Two checks: **(a) suspend/resume while
+      docked** (lid closed, external on) — suspend, resume; pass = you land
+      back docked on the external with the panel still off and remembered
+      external-keyboard layouts intact (the wake now runs the full undock,
+      which `restore_keyboards` after any reload; the old mini did not). **(b)
+      zero-output rescue** — the #127 case (dock mode, external gone/black,
+      eDP disabled): pass = the internal panel comes back lit, workspaces move
+      to it, and `~/nomarchy-display-dump-*.txt` is written iff it stays dark.
+      Watch for a regression: the full undock clears dock-intent, so confirm a
+      *transient* zero-output blip on resume while genuinely still docked does
+      not leave you undocked with the laptop panel on (the external re-add
+      should re-dock via the watcher — verify it does).
 
 ## AMD dev box only
 - [ ] **#118 smartd still runs where drives DO have SMART** (this commit) — the