feat(adr-117/p4): pure-Python WS/MQTT client layer

New sub-package `wifi_densepose.client` (no PyO3, no Rust deps):

- ws.SensingClient — asyncio websockets>=12 wrapper for the Rust
  sensing-server /ws/sensing endpoint. Yields typed dataclasses
  (ConnectionEstablishedMessage, EdgeVitalsMessage, PoseDataMessage)
  with raw-payload fallback for forward-compat with unknown types.
  Malformed frames log+drop without breaking the stream.

- mqtt.RuViewMqttClient — paho-mqtt v2 wrapper using the explicit
  CallbackAPIVersion.VERSION2 API. Per-instance unique client_id by
  default (rumqttc memory lesson). MQTT v5-spec-correct topic
  wildcard matcher: + as whole-level wildcard, # matches the prefix
  itself plus all sub-levels. Auto-resubscribes on reconnect.
  Handler exceptions are caught and logged so a misbehaving callback
  can't crash the network loop.

- primitives.SemanticPrimitiveListener — typed router for the 10
  HA-MIND fused inference outputs from ADR-115 §3.12
  (SomeoneSleeping, PossibleDistress, RoomActive, ElderlyInactivity-
  Anomaly, MeetingInProgress, BathroomOccupied, FallRiskElevated,
  BedExit, NoMovementSafety, MultiRoomTransition). Decodes both
  JSON payloads with confidence+explanation AND plain HA state
  strings ("ON"/"OFF"/numeric). Pluggable into RuViewMqttClient.

- ha.HABlueprintHelper — read-only parser for the
  homeassistant/<kind>/wifi_densepose_<node>/<id>/config payload
  family. Aggregator queries: entities_for_node, by_device_class,
  nodes. Useful for blueprint authors + dashboard introspection.

Test coverage (63 new tests, 156 total in Python suite):
- test_client_ha — 18 tests (topic+payload parsing, aggregator)
- test_client_primitives — 13 tests (enum coverage, listener routing)
- test_client_mqtt — 17 tests (matcher parametrize, dispatch path,
  on_connect, exception isolation) — no broker needed
- test_client_ws — 6 tests including end-to-end against an in-process
  websockets.serve() fixture exercising all 4 message types plus a
  malformed-frame survival check

Post-bridge wheel size: 238 KB (well under ADR §5.4 5 MB budget).

Refs: docs/adr/ADR-117-pip-wifi-densepose-modernization.md §5.6
Refs: docs/adr/ADR-115-home-assistant-integration.md §3.12
Refs: #785

Co-Authored-By: claude-flow <ruv@ruv.net>

python/tests/test_client_primitives.py

@@ -0,0 +1,180 @@
+"""ADR-117 P4 — Tests for the HA-MIND semantic primitive listener.
+
+Pure routing tests — no MQTT broker needed.
+"""
+
+from __future__ import annotations
+
+import json
+
+from wifi_densepose.client import (
+    SemanticPrimitive,
+    SemanticPrimitiveEvent,
+    SemanticPrimitiveListener,
+)
+
+
+# ─── SemanticPrimitive enum ──────────────────────────────────────────
+
+
+def test_enum_covers_all_10_v1_primitives() -> None:
+    expected = {
+        "someone_sleeping",
+        "possible_distress",
+        "room_active",
+        "elderly_inactivity",
+        "meeting_in_progress",
+        "bathroom_occupied",
+        "fall_risk_elevated",
+        "bed_exit",
+        "no_movement_safety",
+        "multi_room_transition",
+    }
+    actual = {p.value for p in SemanticPrimitive}
+    assert actual == expected
+
+
+def test_enum_from_object_id_round_trips() -> None:
+    for p in SemanticPrimitive:
+        assert SemanticPrimitive.from_object_id(p.value) is p
+
+
+def test_enum_from_object_id_returns_none_for_unknown() -> None:
+    assert SemanticPrimitive.from_object_id("garbage") is None
+
+
+# ─── Listener routing ────────────────────────────────────────────────
+
+
+def test_listener_dispatches_to_specific_handler() -> None:
+    listener = SemanticPrimitiveListener()
+    received: list[SemanticPrimitiveEvent] = []
+    listener.on(SemanticPrimitive.SomeoneSleeping, received.append)
+
+    evt = listener.handle_mqtt_message(
+        "homeassistant/binary_sensor/wifi_densepose_aabb/someone_sleeping/state",
+        json.dumps({"state": "ON", "confidence": 0.92, "explanation": ["motion<5%"]}),
+    )
+    assert evt is not None
+    assert evt.kind is SemanticPrimitive.SomeoneSleeping
+    assert evt.node_id == "aabb"
+    assert evt.state == "ON"
+    assert evt.confidence == 0.92
+    assert evt.explanation == ("motion<5%",)
+    assert len(received) == 1
+    assert received[0] is evt
+
+
+def test_listener_on_any_fires_for_every_primitive() -> None:
+    listener = SemanticPrimitiveListener()
+    seen: list[SemanticPrimitiveEvent] = []
+    listener.on_any(seen.append)
+
+    listener.handle_mqtt_message(
+        "homeassistant/binary_sensor/wifi_densepose_aabb/room_active/state",
+        json.dumps({"state": "ON"}),
+    )
+    listener.handle_mqtt_message(
+        "homeassistant/binary_sensor/wifi_densepose_aabb/bathroom_occupied/state",
+        json.dumps({"state": "OFF"}),
+    )
+    assert len(seen) == 2
+    assert seen[0].kind is SemanticPrimitive.RoomActive
+    assert seen[1].kind is SemanticPrimitive.BathroomOccupied
+
+
+def test_listener_specific_handler_does_not_fire_for_other_primitives() -> None:
+    listener = SemanticPrimitiveListener()
+    received: list[SemanticPrimitiveEvent] = []
+    listener.on(SemanticPrimitive.PossibleDistress, received.append)
+
+    listener.handle_mqtt_message(
+        "homeassistant/binary_sensor/wifi_densepose_aabb/someone_sleeping/state",
+        json.dumps({"state": "ON"}),
+    )
+    assert received == []
+
+
+def test_listener_decodes_plain_state_string() -> None:
+    """HA convention: binary_sensors that don't carry attributes emit
+    plain strings ('ON' / 'OFF'). We must accept that too."""
+    listener = SemanticPrimitiveListener()
+    evt = listener.handle_mqtt_message(
+        "homeassistant/binary_sensor/wifi_densepose_aabb/room_active/state",
+        "ON",
+    )
+    assert evt is not None
+    assert evt.state == "ON"
+    assert evt.confidence == 0.0  # not provided in plain string
+    assert evt.explanation == ()
+
+
+def test_listener_decodes_numeric_sensor_state() -> None:
+    """fall_risk_elevated is a 0–100 sensor — verify numeric string."""
+    listener = SemanticPrimitiveListener()
+    evt = listener.handle_mqtt_message(
+        "homeassistant/sensor/wifi_densepose_aabb/fall_risk_elevated/state",
+        "73",
+    )
+    assert evt is not None
+    assert evt.kind is SemanticPrimitive.FallRiskElevated
+    assert evt.state == "73"
+
+
+def test_listener_decodes_bytes_payload() -> None:
+    listener = SemanticPrimitiveListener()
+    evt = listener.handle_mqtt_message(
+        "homeassistant/binary_sensor/wifi_densepose_aabb/room_active/state",
+        b"ON",
+    )
+    assert evt is not None
+    assert evt.state == "ON"
+
+
+def test_listener_ignores_non_state_topics() -> None:
+    listener = SemanticPrimitiveListener()
+    assert listener.handle_mqtt_message(
+        "homeassistant/binary_sensor/wifi_densepose_aabb/room_active/config",
+        json.dumps({"name": "Room Active"}),
+    ) is None
+
+
+def test_listener_ignores_unknown_slug() -> None:
+    listener = SemanticPrimitiveListener()
+    assert listener.handle_mqtt_message(
+        "homeassistant/binary_sensor/wifi_densepose_aabb/unknown_primitive/state",
+        "ON",
+    ) is None
+
+
+def test_listener_ignores_non_wifi_densepose_node() -> None:
+    listener = SemanticPrimitiveListener()
+    # third segment doesn't start with wifi_densepose_
+    assert listener.handle_mqtt_message(
+        "homeassistant/binary_sensor/aqara_fp2/room_active/state",
+        "ON",
+    ) is None
+
+
+def test_listener_explanation_string_is_normalised_to_tuple() -> None:
+    """Producers may send `explanation` as a single string by mistake;
+    accept that and wrap in a 1-tuple so downstream code can iterate
+    uniformly."""
+    listener = SemanticPrimitiveListener()
+    evt = listener.handle_mqtt_message(
+        "homeassistant/binary_sensor/wifi_densepose_aabb/possible_distress/state",
+        json.dumps({"state": "ON", "explanation": "HR=120 baseline=80"}),
+    )
+    assert evt is not None
+    assert evt.explanation == ("HR=120 baseline=80",)
+
+
+def test_event_is_frozen() -> None:
+    evt = SemanticPrimitiveEvent(
+        kind=SemanticPrimitive.SomeoneSleeping,
+        node_id="aabb",
+        state="ON",
+    )
+    import pytest
+    with pytest.raises((AttributeError, Exception)):  # FrozenInstanceError subclass
+        evt.state = "OFF"  # type: ignore[misc]