docs(camera): lane presence + ANPR subscriber-entry bridge design

Captures this session's back-and-forth as a new concept page
[[lane-presence-and-anpr-entry]] and cross-links it:

- BUILT: advisory lane busy/free booth lights (LaneStatus + WS), with the
  measured camera limits behind the 30s timeout (no leave signal; movement-
  driven re-fire; notificationRecurrence locked to "beginning" — ISAPI flip
  silently reverts).
- PLANNED: the ANPR "bridge" — explicitly a small apps/server HANDLER (~40
  lines), NOT a new service/container. On a camera vehicle event: snapshot ->
  ANPR -> high-confidence match -> debounce -> emitRead{kind:"plate"}, then
  the existing subscription match/dispatch/gate admits the subscriber. Both
  directions, opt-in (config.anpr), plate never the sole authority.
- Records the decisions (high confidence floor, debounce-for-correctness)
  and the REJECTED ideas (continuous livestream / per-car queue tracking /
  make-model) with why, plus the open hardware question (booth-PC test).

Updates subscription.md (plate matching is built; the live source is this
bridge) and lpr-camera.md (the two consumers of the vehicle event).

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

wiki/log.md

@@ -1412,3 +1412,22 @@ is unmet; vendor status-API error strings are unreliable. Confirmed real payload
 targetType=vehicle (vehicle/human classified ON-DEVICE), targetRect bounding box. The push endpoint +
 all-methods + skipSourceIpCheck + rejection-recording are all validated against the real device now.
 See [[lpr-camera]] (corrected).
+
+## [2026-06-22] design+build | Lane presence (BUILT) + ANPR subscriber-entry "bridge" (PLANNED)
+Off the now-working Hik vehicle event: BUILT advisory lane busy/free booth barrier lights
+(LaneStatus + WS; timeout-driven "free" since the camera sends no leave signal — TTL settled at 30s
+after a controlled in/out test showed movement-driven ~1-3s re-fire but ~15-25s gaps for a still
+car, and ~no dwell lag on leave). Measured the camera's hard limits: no current-state poll exists,
+and flipping notificationRecurrence beginning->recurring via ISAPI is silently reverted (firmware
+locked). Then narrowed the bigger ambition to a clean, high-value scope: ANPR for SUBSCRIBERS ONLY —
+a plate read at the lane admits a subscriber through the EXISTING gated subscription flow. Found the
+whole subscription side already supports via:"plate" (match + dispatch + gate); the one missing piece
+is a small `apps/server` HANDLER ("the bridge", ~40 lines, NOT a new service/container) that on a
+camera vehicle event snapshots -> ANPR -> on a HIGH-confidence match (new VISION_ENTRY_MIN_CONFIDENCE)
+-> debounces (required for ledger correctness, not CPU: ~1Hz re-fire would drive repeat entries) ->
+emitRead{kind:"plate"}. Both directions, opt-in per camera (config.anpr), plate never the sole
+authority (routes through the gate). REJECTED: continuous livestream presence + per-car queue
+tracking/make-model (needs a vehicle detector the plate-only vision lacks + appliance compute we can't
+measure on the dev PC). Vision checked: fast_alpr live, ~50ms/frame on DEV PC (appliance TBD —
+booth-PC test ~2026-06-23). New page [[lane-presence-and-anpr-entry]]; updated [[lpr-camera]],
+[[subscription]], index.