feat(audio,menu): dock audio auto-follow watcher + docked Display/Audio menu rows

Bernardo's dock test (the #87 V3): audio stayed on EasyEffects→speakers.
Root cause, established live: WirePlumber's stored default
(default-nodes state, written by any past explicit pick) outranks the
priority.session rules, so #87 alone can never move the default on a
real machine; EasyEffects 8 follows the default device (kcfg default
true, verified by watching its output links). Fix: nomarchy-dock-audio
(modules/home/dock-audio.nix, nomarchy.dockAudio.enable, default on) —
a pactl-subscribe watcher that set-default-sinks new dock-class sinks
(regex data imported from modules/nixos/dock-audio-rules.nix, single
source) with a toast, plus a startup sweep for login-while-docked that
never overrides a manual in-dock pick. Unplug falls back by priority.

Menus: Display gains docked rows — "Laptop screen off · everything →
<ext>" (live-only disable; a persisted one could black-screen an
undocked boot), "Screen on · <name>", "Move workspace · → next
monitor", "Swap workspaces" (exactly-2 gate); Audio gains a self-gated
"Send output → <dock sink>" quick row. All self-gate on real outputs.

Verified: V2-equivalent on live hardware (no dock available) — watcher
followed a fake dock-named null sink and fell back on unload, control
run without the watcher stayed pinned (proving the stored-default
diagnosis), EE output links moved mid-playback; generated menu bash -n
green, dock-row jq exercised on real pactl JSON, dispatchers probed on
live Hyprland; flake check + option-docs + template-sot green.
V3 pending: real-dock retest ×2 in HARDWARE-QUEUE (watcher keys on
new-sink events; pre-existing nodes that only flip route availability
would need the queued diagnosis data).

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

modules/home/default.nix

@@ -28,6 +28,7 @@
     ./mime.nix      # default applications (mimeapps.list), degrades with the suite
     ./recording.nix # nomarchy-record: screen recording behind Capture + the bar ⏺
     ./battery-notify.nix # low-battery toasts at the bar's 25/10% thresholds
+    ./dock-audio.nix     # default sink follows dock/monitor audio on hotplug (#87)
     ./first-boot.nix     # one-shot "you're set" toast on first session (#81)
     ./satty.nix     # satty screenshot annotation tool, themed
   ];