fix(docking): retry the undock; a lost keyword left the panel black

Round 6 passed on the plug side but unplugging the cable left the laptop
panel black until it was re-docked. The journal named it: across three
undocks, two logged result=enable-timeout and one result=ok — a race, not
a logic error.

Two halves, both needed:

  - `hyprctl keyword monitor eDP-1,preferred,auto,1` is accepted (exit 0)
    while Hyprland is still tearing down the departing external, then
    silently dropped. Re-issue it on every poll for 5s and keep `monitors`
    listing the panel — not hyprctl's exit code — as the only proof.

  - The watcher fired the undock once off the removal event and marked the
    departure handled regardless (`|| true` + awaiting_lid_open=1). Since
    known_outputs had already moved, the set-changed guard never reopened
    and nothing retried, so one lost keyword cost the panel until re-dock.
    The undock is now a queued invariant driven on the 1s tick, bounded at
    6 attempts so a genuinely unenableable panel can't pin the inhibitor.

The VM harness cannot reach this race: QEMU's headless backend aborts
Hyprland if the last active output is deleted while the DRM output is
disabled, so the test must undock before removing DP-1 and never collides
the two. Noted there, and V3 queued as round 7 — unplug 5+ times, since
the old failure only hit ~2 in 3.

Verified: V2 — nix flake check --no-build; monitor-fallback.nix exit 0 in
57s; shellcheck clean. The fix itself is V3 pending.

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

agent/HARDWARE-QUEUE.md

@@ -32,7 +32,40 @@ the **T14s** (webcam case).
       nomarchy-battery-charge-limit.service` stays false, `Result=success`,
       BAT0's `charge_control_end_threshold` still matches the limit, and the
       journal has no new `start-limit-hit`/`Failed with result` lines.
-- [ ] **Docking recovery round 5 (dock/keyboard/audio hotplug, 2026-07-14)**
+- [ ] **Docking recovery round 7 (undock panel restore, 2026-07-14)** —
+      round 6 (AMD dev box, Bernardo) **passed on the plug side**: the dock
+      docked by itself, audio went straight to the monitor, and the wallpaper
+      painted on the external. One count failed: **unplugging the cable left
+      the laptop panel black**, recoverable only by re-docking. The journal
+      named the cause exactly — across three undocks, two logged
+      `transition=undock internal=eDP-1 result=enable-timeout` and one
+      `result=ok`, i.e. an intermittent race, not a logic error. Both halves
+      are fixed in the commit carrying this entry: `hyprctl keyword monitor
+      eDP-1,preferred,auto,1` is *accepted* (exit 0) while Hyprland is still
+      tearing down the departing external and then silently dropped, so the
+      transition now re-issues it on every poll for 5s rather than trusting
+      one shot; and the watcher no longer treats a failed undock as final —
+      the departure is queued and retried on the 1s tick (up to 6 attempts)
+      instead of being marked handled with `|| true`, which is what turned one
+      lost keyword into a panel dark until re-dock. **The VM harness cannot
+      reach this** (`tools/monitor-fallback.nix`: QEMU's headless backend
+      aborts Hyprland if the last active output is deleted while the DRM
+      output is disabled, so the test must undock *before* removing DP-1 and
+      never collides the two) — hardware is the only place it can be proven.
+      **Re-check:** relogin (mandatory — see below), dock, then unplug the
+      cable **at least five times**, since the old failure only hit ~2 of 3.
+      **Pass:** the panel comes back every single time with workspaces intact,
+      and `journalctl --user -t nomarchy-display-transition -t
+      nomarchy-display-watch --since '-10 min'` shows a
+      `transition=undock result=ok attempts=N` for each undock and **never**
+      `result=gave-up`. `attempts=2` or more is the retry doing its job and is
+      a pass; `gave-up` means the panel could not be enabled at all and is a
+      different fault — capture the artifacts listed in round 4 before
+      changing state.
+- [ ] **Docking recovery round 5/6 (keyboard + headphone-jack counts,
+      2026-07-14)** — round 6 confirmed the dock/audio/wallpaper counts
+      below; the **keyboard-prompts-exactly-once** and **headphone
+      plug/unplug** counts were not reported either way and still need a run.
       — round 4 was run on the AMD dev box and **failed on four counts**
       (Bernardo): no wallpaper on the external monitor, no automatic dock
       mode (System › Display had to be used by hand), audio staying on the