D key doesn't reliably launch Dashboard or reflect its running state

[dubpixel]

Bug

The D key on the deck splash doesn't reliably work — reported as two symptoms, may be one root cause or two separate bugs:

1. Doesn't launch Dashboard — pressing D doesn't actually start it
2. Doesn't reflect the running state — the key's color (red = running, gray = installed but off) doesn't accurately show what Dashboard is actually doing

Likely explanation for (1), needs confirming

The D-key press-to-toggle feature (--toggle-dashboard CLI flag, sudoers entry, on_key wiring) was added in 56baa75, but no build has been made from that commit yet — every currently-flashed device (rockpi-s, both Pi 4 units) predates it. On those builds, D was always display-only by design (see gotcha in draw_dashboard_key's original docstring), so "doesn't launch" on current hardware is expected until a fresh build/flash happens from main post-56baa75.

Needs a fresh build + flash to actually test whether the toggle itself works at all.

(2) needs real investigation regardless

The status-reflection logic (draw_dashboard_key/dashboard_active()) predates 56baa75 and should already be live on current hardware — if it's genuinely not reflecting real state (not just "toggle doesn't do anything because old build"), that's a separate, real bug worth checking directly once there's SSH/console access to a device with Dashboard actually installed. Check systemctl is-active dpx-dashboard against what the key is actually showing.

Notes

• From Josh's feedback on the latest Pi build — same "real hardware surfaces bugs a clean build can't" pattern as gotchas D key doesn't reliably launch Dashboard or reflect its running state #17-26
• Worth checking on both Pi 4 (Raspberry Pi OS) and rockpi-s (Armbian) once retested, per the "issues on one side may apply to the other" concern raised alongside this