fix live polling to use effective agent from site/org cascade

live poll mode used get_device_assignment which only checks direct
device-level assignments. devices with agent assigned at site or
org level fell through to direct Phoenix SNMP. replaced with
get_effective_agent_token which walks the full cascade.

CHANGELOG.txt

@@ -1,6 +1,15 @@
 CHANGELOG - towerops-web
 ========================
 
+2026-02-11 - fix: live polling uses effective agent from site/org cascade
+  - File: lib/towerops_web/live/graph_live/show.ex
+  - Bug: Live poll mode used Agents.get_device_assignment/1 which only checks
+    direct device-level assignments. Devices with agent assigned at site or
+    org level fell through to direct Phoenix SNMP instead of routing to agent.
+  - Fix: Replaced with Agents.get_effective_agent_token/1 which walks the
+    device → site → org cascade, matching how regular polling resolves agents.
+    Also simplified request_agent_live_poll_and_wait to accept token_id directly.
+
 2026-02-11 - fix: round sensor values to 1 decimal place
   - Files: lib/towerops/workers/device_poller_worker.ex (poll_simple_sensor/2),
            lib/towerops_web/channels/agent_channel.ex (process_sensor_reading/3)

lib/towerops_web/live/graph_live/show.ex

@@ -686,16 +686,16 @@ defmodule ToweropsWeb.GraphLive.Show do
     now = DateTime.utc_now()
     timestamp_ms = DateTime.to_unix(now, :millisecond)
 
-    # Check if device has agent assignment (fresh check each poll to avoid stale data)
-    has_agent = Agents.get_device_assignment(device.id) != nil
+    # Check effective agent (device → site → org cascade)
+    agent_token_id = Agents.get_effective_agent_token(device)
 
-    Logger.info("Live poll for device #{device.name}: has_agent=#{has_agent}")
+    Logger.info("Live poll for device #{device.name}: agent_token_id=#{inspect(agent_token_id)}")
 
     new_points =
-      if has_agent do
+      if agent_token_id do
         # Request agent to poll NOW and wait for result
         Logger.info("Requesting live poll from agent")
-        request_agent_live_poll_and_wait(device.id, socket.assigns)
+        request_agent_live_poll_and_wait(device.id, agent_token_id, socket.assigns)
       else
         # Do direct SNMP polling for specific sensors only
         Logger.info("Using direct SNMP for live polling")
@@ -724,39 +724,33 @@ defmodule ToweropsWeb.GraphLive.Show do
   end
 
   # Request live poll from agent and wait for response
-  defp request_agent_live_poll_and_wait(device_id, assigns) do
-    case Agents.get_device_assignment(device_id) do
-      nil ->
+  defp request_agent_live_poll_and_wait(device_id, agent_token_id, assigns) do
+    # Generate unique reply topic for this request
+    reply_topic = "live_poll_reply:#{:erlang.unique_integer([:positive])}"
+
+    # Subscribe to reply topic
+    :ok = Phoenix.PubSub.subscribe(Towerops.PubSub, reply_topic)
+
+    # Get sensors we're interested in
+    sensors = get_sensors_for_live_mode(assigns)
+    sensor_oids = Enum.map(sensors, & &1.sensor_oid)
+
+    # Broadcast live poll request with reply topic and sensor OIDs
+    Phoenix.PubSub.broadcast(
+      Towerops.PubSub,
+      "agent:#{agent_token_id}:live_poll",
+      {:live_poll_requested, device_id, sensor_oids, reply_topic}
+    )
+
+    # Wait for response with timeout
+    receive do
+      {:live_poll_result, oid_values} ->
+        # Process the OID values into data points
+        process_live_poll_oids(sensors, oid_values)
+    after
+      3000 ->
+        Logger.warning("Live poll timeout waiting for agent response")
         []
-
-      assignment ->
-        # Generate unique reply topic for this request
-        reply_topic = "live_poll_reply:#{:erlang.unique_integer([:positive])}"
-
-        # Subscribe to reply topic
-        :ok = Phoenix.PubSub.subscribe(Towerops.PubSub, reply_topic)
-
-        # Get sensors we're interested in
-        sensors = get_sensors_for_live_mode(assigns)
-        sensor_oids = Enum.map(sensors, & &1.sensor_oid)
-
-        # Broadcast live poll request with reply topic and sensor OIDs
-        Phoenix.PubSub.broadcast(
-          Towerops.PubSub,
-          "agent:#{assignment.agent_token_id}:live_poll",
-          {:live_poll_requested, device_id, sensor_oids, reply_topic}
-        )
-
-        # Wait for response with timeout
-        receive do
-          {:live_poll_result, oid_values} ->
-            # Process the OID values into data points
-            process_live_poll_oids(sensors, oid_values)
-        after
-          3000 ->
-            Logger.warning("Live poll timeout waiting for agent response")
-            []
-        end
     end
   end