feat(booth): blink the Entry/Exit lights on radar presence (mirror relay 3)

The on-screen Hyrje/Dalje barrier lights were 2-state (green=free / red=busy)
off the camera lane-status only — they couldn't show the radar-only "detected,
not yet confirmed" state that makes the physical button lamp (relay 3) blink.
Now they mirror the lamp's 3-state rule per lane:
  radar present + camera not busy → BLINK green↔red (~1 Hz)
  camera busy                     → SOLID red
  otherwise                       → SOLID green

End-to-end:
- LanePresence (lane-presence.ts): subscribes to deviceEvents.onInput, resolves
  each presence edge to its lane via the new direction-agnostic presenceLaneOf()
  (device-resolve.ts) — entry AND exit, unlike the entry-gated relayForPresence
  the one-car-one-ticket gate uses — and emits a lane-presence {entry,exit} bus
  event on change. Wired in server.ts (start + onClose).
- WS forwards it (hello snapshot + push) into live-store.radar.
- BarrierLight (BoothScreen.tsx) is now 3-state; blinks via the .lane-blink
  keyframe (index.css), which holds solid-red under prefers-reduced-motion.

Same input + same rule as the lamp, so the screen and the post never disagree.

A new test (lane-presence.test.ts) caught a real bug: the first cut reused
relayForPresence, so the EXIT lane never resolved (it's entry-gated) and never
blinked — presenceLaneOf fixes it. Covers entry/exit independence, de-dupe
across several radars on one lane, and ignoring non-presence inputs.

Full workspace build/lint/test green (185 server tests). Updated the
button-light-indicator wiki page ("On-screen twin").

Claude-Session: https://claude.ai/code/session_01Xcm6ikLgGoCxxHrxtjkk5V

wiki/log.md

@@ -1794,3 +1794,19 @@ resolution + legacy-fallback identical + exit-radar resolves to the exit relay),
 case in `button-light.test.ts`, `activeLowFrom` cases in the dingtian suite. Full workspace
 `build lint test` green. Updated [[entry-double-press]], [[button-light-indicator]], [[dingtian-relay]],
 memory `access-direction-is-per-relay`.
+
+## [2026-06-28] feat | Booth Entry/Exit lights blink on radar presence (mirror relay 3)
+The on-screen Hyrje/Dalje barrier lights were 2-state (green=free / red=busy) off the camera
+lane-status only — they couldn't show the radar-only "detected, not yet confirmed" state that makes
+the physical button lamp (relay 3) blink. Added that signal end-to-end: a small server tracker
+**`LanePresence`** (lane-presence.ts) subscribes to `deviceEvents.onInput`, resolves each presence
+edge to its lane via a new **`presenceLaneOf`** (device-resolve.ts) — direction-agnostic (entry AND
+exit), unlike the entry-gated `relayForPresence` — and emits a `lane-presence {entry,exit}` bus
+event on change. The WS forwards it (hello snapshot + push) into `live-store.radar`; `BarrierLight`
+(BoothScreen.tsx) became **3-state**, mirroring relay 3 exactly: radar+camera-free → BLINK green↔red
+~1 Hz (`.lane-blink` keyframe in index.css, holds solid-red under prefers-reduced-motion);
+camera-busy → SOLID red; else SOLID green. Same input + same rule as the lamp, so screen and post
+never disagree. A test (lane-presence.test.ts) caught a real bug: the first cut reused
+`relayForPresence`, so the EXIT lane never resolved (entry-gated) and never blinked —
+`presenceLaneOf` fixes it. Full workspace build/lint/test green (185 server tests). Updated
+[[button-light-indicator]] (new "On-screen twin" section).