feat(vision): wire ANPR into the read bus via VisionReader

A VisionReader polls each opt-in camera (config.anpr===true, off by default) every
VISION_POLL_MS, captures a snapshot, recognizes via VisionClient, and on a confident
plate emits deviceEvents.emitRead({kind:"plate", value}) — the same event a physical
plate reader sends, so the existing ReadDispatcher routes it to the subscription/exit
flow unchanged (no flow rewrite).

The plate stays advisory by construction: the exit flow still demands a covering
payment, the subscription flow only matches a bound plate. Guards: low-confidence reads
dropped; debounce (VISION_DEDUPE_MS) so a parked car doesn't re-fire; per-camera
in-flight guard; idle when vision is off or no camera opts in. #recognizeOn is public
for a future on-demand (loop-edge/API) trigger.

Verified end-to-end: an in-memory anpr camera (AL plate image) + live fast_alpr service
→ VisionReader emitted exactly one {kind:"plate",value:"AA558EE"} onto the bus; debounce
held it to 1 emit over 7 polls. Build + lint green. Updates opencv-anpr-service
(trigger-wiring + per-camera opt-in marked done).

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

wiki/entities/opencv-anpr-service.md

@@ -170,14 +170,22 @@ the read is given** — and the answer splits by role:
 now exists: **opt-in** (`VISION_ENABLED`, default off), **fail-soft** (any error/timeout/unreachable →
 `null`, never throws into the lane → ticket-path fallback), and **re-applies the confidence floor**
 (`VISION_MIN_CONFIDENCE`) so a low read is flagged advisory. Constructed in `server.ts`; verified
-end-to-end against the live service (Node → `AA558EE` 0.999, `region=Albania`). Still NOT wired into the
-read bus. (2) **trigger wiring** — snapshots today fire *after* a barrier opens (evidence);
-plate-as-identity needs a snapshot *before* the decision, on a **per-camera opt-in** lane → emit
-`DeviceReadEvent{kind:"plate"}` (open item below). (3) **field-accuracy** unknown — re-benchmark/tune
+end-to-end against the live service (Node → `AA558EE` 0.999, `region=Albania`). (2) ✅ **DONE —
+trigger wiring (`apps/server/src/vision-reader.ts`).** A **`VisionReader`** polls each **opt-in**
+camera (`config.anpr === true`, off by default) every `VISION_POLL_MS`, captures a snapshot →
+`VisionClient.analyze` → on a **confident** plate emits a `DeviceReadEvent{kind:"plate"}` onto the
+**same read bus a physical reader uses** (`deviceEvents.emitRead`), so the `ReadDispatcher` routes it
+to the subscription/exit flow **unchanged**. Guards: low-confidence reads are dropped (not an
+identity); a **debounce** (`VISION_DEDUPE_MS`) stops the same plate re-firing while a car sits in
+frame; an in-flight guard prevents overlapping recognizes; idle when vision is off or no camera opts
+in. Verified end-to-end (live service → reader → one `AA558EE` read on the bus; debounce held it to 1
+emit over 7 polls). Plate stays **advisory** — the exit flow still demands a `payment`, the
+subscription flow only matches a **bound** plate. (3) **field-accuracy** unknown — re-benchmark/tune
 the threshold on real on-site captures (angle/night/dirt). (4) the **weight-provenance** check (open).
 **Bottom line: consume it as a gated advisory identity source feeding the existing `kind:"plate"` path
-— not as sole authority — and Job 2 is still required for the anti-spoofing value.** With the adapter
-done, the next concrete step is the **opt-in snapshot→read trigger**, not more model work.
+— not as sole authority — and Job 2 is still required for the anti-spoofing value.** The
+adapter + the opt-in poll→read trigger are now **both built and verified end-to-end**; remaining is
+field tuning (3), the provenance check (4), the SetupWizard `anpr` toggle, and Job 2.
 
 ## Open
 
@@ -190,5 +198,6 @@ done, the next concrete step is the **opt-in snapshot→read trigger**, not more
   mismatch an anomaly without false-positiving on lighting/angle.
 - **Compute footprint** on the appliance (CPU-only vs. a small GPU/NPU) — procurement input
   ([[bom]], [[open-questions]]).
-- Per-camera **opt-in** ("optionally bound", user's word): which lanes/cameras route snapshots to
-  the service.
+- Per-camera **opt-in** — ✅ **mechanism built**: `config.anpr === true` on a camera enables ANPR
+  polling (the `VisionReader`). Remaining: expose the toggle in the **SetupWizard** (it's currently
+  set in raw config) and decide sensible `VISION_POLL_MS`/`VISION_DEDUPE_MS` defaults per site.