Add Daikin local-API driver — MAC-matched subnet sweep instead of UDP broadcast

Daikin BRP069/BRP072-class units are WiFi/DHCP with no fixed IP. hvac's backend
runs as a Docker container on its own bridge network (not directly on the LXC's
admin-VLAN NIC), so UDP broadcast discovery risked silently failing to egress —
instead, every unit is identified by MAC (external_ref), and a background poller
periodically HTTP-sweeps the configured subnet CIDR and matches replies by MAC,
self-healing zone_devices.device_ip whenever a lease changes. Only needs plain
outbound HTTP, same path already proven by the MHI Modbus TCP driver.

- lib/drivers/daikin.js: discover()/getStatus()/setTarget() against the local
  /common/basic_info + /aircon/get_control_info + /aircon/set_control_info API
  (confirmed live against firmware 4_2_303, 2026-08-25). Mode/fan-rate encoding
  taken from community reverse-engineering, not yet verified against a live
  setTarget() call — flagged in comments for first real control test.
- lib/daikin-poller.js: 60s status poll (cached IP) + 5min subnet resweep
  (self-heal IP + auto-register new units, never auto-assigned to a zone).
- lib/device-registry.js: shared discover-upsert, extracted so both the manual
  Discover button and the background sweep record device_ip the same way.
- ac-control.js / routes/override.js: daikin-status/daikin-control endpoints
  and commandAcDevice() branch, mirroring the existing MHI control path.
- Settings page: new "Daikin subnet (CIDR)" field (daikin_subnet_cidr config
  key) — sweeps do nothing until this is set.
- Frontend: DaikinControlPanel.tsx (on/off/mode/setpoint/fan), wired into
  ZoneDetailModal; daikin moved from NOT_YET_IMPLEMENTED to a real driver.

Backend node --check and frontend tsc --noEmit both clean.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

backend/src/routes/devices.js

@@ -6,24 +6,29 @@ import { requireAuth, requireCap } from '../auth.js'
 import { pool, logActivity } from '../db.js'
 import * as trvDriver from '../lib/drivers/trv.js'
 import * as haDriver from '../lib/drivers/homeassistant.js'
+import * as daikinDriver from '../lib/drivers/daikin.js'
 import { createMaintenanceAsset } from '../lib/maintenance-client.js'
+import { upsertDiscovered } from '../lib/device-registry.js'
 
 const ALLOWED_IMAGES = ['image/jpeg', 'image/jpg', 'image/png', 'image/webp']
 const PHOTO_TYPES = ['device', 'serial_plate']
 
-// device_type -> driver implementing discover()/getStatus()/setTarget(). Phase 3
-// types (midea, daikin) are enum values only — no driver yet. mhi_modbus DOES
-// have a driver (lib/drivers/mhi-modbus.js) but it isn't wired into this generic
-// no-args discover flow — Modbus has no broadcast scan, and discover() there
-// needs a specific already-configured gateway, so it's only ever called from
-// routes/mhi-gateways.js's test-connection route. Units are onboarded via
-// "Gateways" (Devices page): configure a gateway, import its MAPS register map,
-// then assign units to zones — never via this Discover button.
+// device_type -> driver implementing discover()/getStatus()/setTarget(). midea is
+// still an enum value only — no driver yet. mhi_modbus DOES have a driver
+// (lib/drivers/mhi-modbus.js) but it isn't wired into this generic no-args discover
+// flow — Modbus has no broadcast scan, and discover() there needs a specific
+// already-configured gateway, so it's only ever called from routes/mhi-gateways.js's
+// test-connection route. Units are onboarded via "Gateways" (Devices page): configure
+// a gateway, import its MAPS register map, then assign units to zones — never via
+// this Discover button. daikin's discover() does a full-subnet HTTP sweep (no
+// broadcast — see lib/drivers/daikin.js) so it fits this generic flow fine, but
+// needs "Daikin subnet (CIDR)" set on the Settings page first.
 const DRIVERS = {
   shelly_trv: trvDriver,
   home_assistant: haDriver,
+  daikin: daikinDriver,
 }
-const NOT_YET_IMPLEMENTED = ['midea', 'daikin']
+const NOT_YET_IMPLEMENTED = ['midea']
 const MHI_MODBUS_NOTE = "MHI aircon units aren't found via Discover — configure a gateway and import its register " +
   'map under Devices -> Gateways, then assign units to zones there.'
 const MHI_MQTT_NOTE = 'MHI aircon units on native MQTT self-register as they publish status — they appear ' +
@@ -71,21 +76,10 @@ export async function deviceRoutes(app, opts) {
     if (!driver) return reply.status(400).send({ error: `Unknown device_type: ${device_type}` })
 
     const result = await driver.discover()
-    if (!result.ok) return reply.status(200).send(result) // e.g. broker/HA not reachable — not a hard error
+    if (!result.ok) return reply.status(200).send(result) // e.g. broker/HA/CIDR not configured — not a hard error
 
-    let discoveredCount = 0
-    for (const d of result.devices) {
-      const res = await pool.query(
-        `INSERT INTO zone_devices (device_type, external_ref, discovered_name)
-         VALUES ($1, $2, $3)
-         ON CONFLICT (device_type, external_ref) DO UPDATE SET discovered_name = EXCLUDED.discovered_name, last_seen = NOW()
-         RETURNING (xmax = 0) AS inserted`,
-        [device_type, d.external_ref, d.discovered_name || d.external_ref]
-      )
-      if (res.rows[0].inserted) discoveredCount++
-    }
-
-    return { ok: true, found: result.devices.length, new: discoveredCount }
+    const discoveredCount = await upsertDiscovered(device_type, result.devices)
+    return { ok: true, found: result.devices.length, new: discoveredCount, note: result.note }
   })
 
   // PATCH /api/devices/:id — zone/location assignment (a living mapping, not a one-time wizard)