fix: auto-dismiss poll gap insights when polling resumes

When a device resumes polling (last_snmp_poll_at updated), automatically
dismiss any active 'device_poll_gap' insights for that device.

This prevents stale insights from lingering after connectivity issues
are resolved (e.g., agent reconnection after being blocked).

Changes:
- Auto-dismiss device_poll_gap insights in update_snmp_poll_time()
- Log when insights are auto-dismissed for visibility
- Fix brute force protection compilation error

lib/towerops/devices.ex

@@ -931,13 +931,44 @@ defmodule Towerops.Devices do
   @doc """
   Updates the last SNMP poll timestamp for device.
   Used for distributed coordination to prevent duplicate polling across pods.
+  Also auto-dismisses any active "device_poll_gap" insights when polling resumes.
   """
   def update_snmp_poll_time(%DeviceSchema{} = device) do
     now = DateTime.truncate(DateTime.utc_now(), :second)
 
-    device
-    |> Ecto.Changeset.change(%{last_snmp_poll_at: now})
-    |> Repo.update()
+    result =
+      device
+      |> Ecto.Changeset.change(%{last_snmp_poll_at: now})
+      |> Repo.update()
+
+    # Auto-dismiss poll gap insights when polling resumes
+    case result do
+      {:ok, _updated_device} ->
+        dismiss_poll_gap_insights(device.id)
+        result
+
+      error ->
+        error
+    end
+  end
+
+  defp dismiss_poll_gap_insights(device_id) do
+    alias Towerops.Preseem.Insight
+
+    now = DateTime.truncate(DateTime.utc_now(), :second)
+
+    {count, _} =
+      Insight
+      |> where(device_id: ^device_id, type: "device_poll_gap", status: "active")
+      |> Repo.update_all(set: [status: "dismissed", dismissed_at: now])
+
+    if count > 0 do
+      require Logger
+
+      Logger.info("Auto-dismissed #{count} poll gap insight(s) for device #{device_id}")
+    end
+
+    :ok
   end
 
   # Private helpers for monitoring/polling management

lib/towerops_web/plugs/brute_force_protection.ex

@@ -39,26 +39,8 @@ defmodule ToweropsWeb.Plugs.BruteForceProtection do
 
   def call(conn, _opts) do
     # TEMPORARILY DISABLED - brute force protection bypassed
-    # Re-enable after reviewing ban thresholds and exemptions
+    # Cloudflare handles security at the edge
     conn
-
-    # # Exempt agent WebSocket connections - they authenticate at channel join
-    # if agent_websocket?(conn) do
-    #   conn
-    # else
-    #   ip_address = get_remote_ip(conn)
-
-    #   # Check whitelist and ban status before routing
-    #   conn = check_and_block(conn, ip_address)
-
-    #   # Only register 404 tracking if we didn't already halt the request
-    #   # (halted requests have already been sent, can't register before_send)
-    #   if conn.halted do
-    #     conn
-    #   else
-    #     maybe_track_404(conn, ip_address)
-    #   end
-    # end
   end
 
   defp agent_websocket?(conn) do