Dingtian input HTTP-push to backend (no polling)

The device pushes button events to the backend via its Input Link URL feature;
the backend decides. No polling — the chosen entry architecture.

packages/devices:
- dingtian driver: configureInputPush() writes the device's input_link_url
  config (per-input server/port/path, en=1, active-LOW, plain HTTP) so each
  input HTTP-GETs the backend on press/release. Extracted #readConfig/#writeConfig
  (with the required command:setconfig injection + post-write reset tolerance).

apps/server:
- routes/devices.ts: public GET/POST
  /api/devices/dingtian/:deviceId/input/:n/{on,off} — translates a device push
  into an internal device event. Not behind cookie/CSRF (machine call from the
  device); trust comes from the signed event log, not this request.
- device-events.ts: internal EventEmitter bus so the entry flow subscribes to
  input events without coupling to HTTP. Wired into the server.

Verified on hardware: configured the device, then real presses on all 4 inputs
pushed to the backend (input N on+off, source = device IP). No polling.

wiki: device-input-flow concept (path + trust model for the flat/no-VLAN
network); dingtian-relay updated; index + log.

wiki/log.md

@@ -131,3 +131,17 @@ device" framing (standing-decisions, bom, overview, open-questions) to
 [[dingtian-relay]]; noted no current driver uses [[device-discovery]]. Transferable
 concepts (network-isolation, event-log-ingestion, barrier-not-a-door, threat-model)
 kept as-is. Links lint clean; raw source untouched (immutable).
+
+## [2026-06-15] feature | Dingtian input HTTP-push → backend (no polling)
+Wired the device's "Input Link URL" feature so it HTTP-pushes button events to
+our backend — no polling. Driver `configureInputPush()` writes input_link_url
+(per-input server/port/path, en=1, active-LOW, plain HTTP) via the config API
+(reusing the #writeConfig + command:setconfig helper). New backend route
+`routes/devices.ts`: public `GET/POST /api/devices/dingtian/:deviceId/input/:n/{on,off}`
+→ emits onto an internal device-events bus (device-events.ts, EventEmitter) for
+the entry flow to consume. VERIFIED on hardware: configured device, real presses
+on all 4 inputs pushed to the backend (input N on+off, source = device IP). Trust
+model recorded in [[device-input-flow]]: flat network / no VLAN → backend is source
+of truth, every open is a signed event (out-of-band open = anomaly); push endpoint
+not behind cookie auth (machine call), shared-secret available as defence-in-depth.
+Next: wire signed event + ticket print + pulseOpen.