Multi-node deployments collapse into a single Home-Assistant device — MQTT discovery hard-codes node_id to 1, contradicting the "one device per node" docs

[mschabhuettl]

Bug Report

Description

After the MQTT wiring fix (PR #874, ghcr.io/ruvnet/wifi-densepose:latest,
image Created: 2026-05-31T15:44:26Z), --mqtt works and the publisher
starts — but every node is published as the same Home-Assistant device
wifi_densepose_wifi-densepose-1, regardless of how many physical ESP32 nodes
are sending CSI frames.

This contradicts docs/integrations/home-assistant.md, which states the
integration creates one device per RuView node.

Expected behaviour

With N nodes provisioned with distinct node-ids/zones, Home Assistant should
auto-discover N devices (one per node/room), each with its own presence /
person-count / motion entities — as the documentation promises.

Actual behaviour

All nodes are merged into a single device with a hard-coded identifier:

"identifiers":["wifi_densepose_wifi-densepose-1"]   "name":"RuView"

The broker logs confirm the publisher connects as a single fixed client:

New client connected ... as wifi-densepose-1 (p4, c1, k30, u'mqtt').
[mqtt] publisher started host=127.0.0.1 port=1883 prefix=homeassistant entities=20 privacy=false

entities=20 = one device, 20 entities — never per-node.

Key contrast: the REST API DOES separate the nodes

The same server's REST endpoint correctly distinguishes every node, with
independent state per node_id:

GET http://<server>:3000/api/v1/nodes
{
  "nodes": [
    { "node_id": 1, "status": "active", "motion_level": "absent",        "person_count": 1 },
    { "node_id": 2, "status": "active", "motion_level": "present_still",  "person_count": 1 }
  ],
  "total": 2
}

So the per-node data exists internally — only the MQTT discovery/publisher
throws it away and emits a single fixed node_id = 1.

Steps to reproduce

1. Provision two (or more) ESP32 nodes with distinct node-ids/zones, all
   targeting the same sensing-server (--source esp32, UDP 5005).
2. Run ghcr.io/ruvnet/wifi-densepose:latest with
   --mqtt --mqtt-host <broker> --mqtt-username <user> (MQTT password via env).
3. Power on two different nodes (e.g. node 1 and node 2).
4. Subscribe to discovery configs:

   mosquitto_sub -t 'homeassistant/+/+/presence/config' -v \
     | grep -o 'wifi-densepose-[0-9]*' | sort -u
   

5. Observed: only wifi-densepose-1.
   Expected: wifi-densepose-1 and wifi-densepose-2.

Root-cause pointer (from source on main)

• v2/crates/wifi-densepose-sensing-server/src/mqtt/publisher.rs holds a
  single OwnedDiscoveryBuilder { node_id: String } (singular). The publisher
  task does not iterate over multiple nodes — there is no
  for node in nodes / per-node map anywhere under src/mqtt/.
• src/mqtt/discovery.rs builds the device identifier from that single id:
  identifiers: vec![format!("wifi_densepose_{}", self.node_id)] — so one
  server instance can only ever describe one device.
• There is no CLI flag to set the identity: --help exposes no
  --node-id, --zone, or --device-name (checked on latest and on
  v0.12.0). --mqtt-client-id only sets the broker connection id, not the
  HA device identifiers.

This means neither a single server nor multiple parallel containers can produce
per-room devices today: a single server merges all nodes onto node_id = 1,
and parallel containers would all publish the identical
wifi_densepose_wifi-densepose-1, colliding into one HA device.

Suggested fix (one of)

• Have the MQTT publisher iterate the live node set (same source the REST
  /api/v1/nodes endpoint already uses) and emit one discovery device per
  node_id, OR
• Add a --node-id / --zone / --device-name flag (and matching
  RUVIEW_* env) so multiple single-node server instances can each own a
  distinct HA device identity.

Environment

• Image: ghcr.io/ruvnet/wifi-densepose:latest, Created 2026-05-31T15:44:26Z
  (i.e. includes the PR Docker images missing MQTT support (--mqtt flag not compiled in) #872 MQTT wiring fix)
• Deployed via Portainer; local mosquitto bridge → upstream broker (plaintext 1883)
• ESP32-S3 CSI nodes, firmware v0.7.0-esp32, provisioned with distinct
  node-ids/zones, all targeting one sensing-server on UDP 5005
• Related: Docker images missing MQTT support (--mqtt flag not compiled in) #872 (MQTT flag not compiled in) — fixed; this is a separate,
  pre-existing per-node-identity gap that the fix does not address.