feat(gaiia): MAC-based auto-matching (phase 1, highest confidence)

Adds MAC address matching as the primary matching phase:
- Normalizes MACs (strips colons/dots/dashes) from SNMP interface data
- Matches against gaiia_inventory_items.mac_address (synced from Gaiia)
- Phase 1: MAC → Phase 2: IP → Phase 3: Site

Flash now shows breakdown: "Auto-matched 47 devices (12 by MAC, 34 by
IP, 1 by site). 17 remaining."

lib/towerops/gaiia.ex

@@ -15,6 +15,7 @@ defmodule Towerops.Gaiia do
   alias Towerops.Repo
   alias Towerops.Sites.Site
   alias Towerops.Snmp.Device, as: SnmpDevice
+  alias Towerops.Snmp.Interface, as: SnmpInterface
   # --- Accounts ---
   alias Towerops.Snmp.WirelessClientReading
 
@@ -136,7 +137,22 @@ defmodule Towerops.Gaiia do
       |> where([i], is_nil(i.device_id))
       |> Repo.all()
 
-    # Phase 1: IP-based matching
+    # Phase 1: MAC-based matching (highest confidence — exact identifier).
+    # Gaiia equipment is assigned by MAC (usually br0), so this catches
+    # devices that have no IP in Gaiia but are already inventoried.
+    unmapped_by_mac =
+      unmapped_items
+      |> Enum.reject(fn i -> is_nil(i.mac_address) or i.mac_address == "" end)
+      |> Enum.group_by(&normalize_mac(&1.mac_address))
+
+    device_macs = build_device_mac_index(organization_id)
+
+    {mac_matched, _after_mac} =
+      match_phase(organization_id, unmapped_by_mac, fn device, items ->
+        mac_matcher(device, items, device_macs)
+      end)
+
+    # Phase 2: IP-based matching
     unmapped_by_ip =
       unmapped_items
       |> Enum.reject(fn i -> is_nil(i.ip_address) or i.ip_address == "" end)
@@ -144,7 +160,7 @@ defmodule Towerops.Gaiia do
 
     {ip_matched, _after_ip} = match_phase(organization_id, unmapped_by_ip, &ip_matcher/2)
 
-    # Phase 2: Site-based matching — devices at a Towerops site linked to a
+    # Phase 3: Site-based matching — devices at a Towerops site linked to a
     # Gaiia network site get matched to inventory items assigned to that site
     site_network_map = build_site_network_map(organization_id)
 
@@ -174,7 +190,7 @@ defmodule Towerops.Gaiia do
 
     remaining = total_devices - MapSet.size(mapped_device_ids)
 
-    {:ok, ip_matched, site_matched, remaining}
+    {:ok, ip_matched, site_matched, mac_matched, remaining}
   end
 
   defp match_phase(organization_id, unmapped_index, matcher_fn) do
@@ -241,6 +257,44 @@ defmodule Towerops.Gaiia do
     end)
   end
 
+  # Builds a map of device_id → normalized MAC address from SNMP interfaces.
+  # Uses the first non-null MAC found — typically the br0/bridge interface.
+  defp build_device_mac_index(organization_id) do
+    SnmpInterface
+    |> join(:inner, [si], sd in SnmpDevice, on: si.snmp_device_id == sd.id)
+    |> join(:inner, [_si, sd], d in Device, on: sd.device_id == d.id)
+    |> where([_si, _sd, d], d.organization_id == ^organization_id)
+    |> where([si], not is_nil(si.mac_address) and si.mac_address != "")
+    |> select([si, sd], {sd.device_id, si.mac_address})
+    |> Repo.all()
+    |> Enum.group_by(fn {device_id, _mac} -> device_id end, fn {_device_id, mac} -> normalize_mac(mac) end)
+  end
+
+  defp mac_matcher(device, unmapped_by_mac, device_macs) do
+    case Map.get(device_macs, device.id) do
+      macs when is_list(macs) and macs != [] ->
+        find_mac_match(macs, unmapped_by_mac)
+
+      _ ->
+        :no_match
+    end
+  end
+
+  defp find_mac_match(macs, unmapped_by_mac) do
+    Enum.find_value(macs, :no_match, fn mac ->
+      case Map.get(unmapped_by_mac, mac) do
+        [item | _rest] -> {:match, item}
+        _ -> nil
+      end
+    end)
+  end
+
+  defp normalize_mac(mac) when is_binary(mac) do
+    mac
+    |> String.downcase()
+    |> String.replace(~r/[:.\-\s]/, "")
+  end
+
   # Builds a map of Towerops site_id → list of Gaiia network site gaiia_ids
   defp build_site_network_map(organization_id) do
     NetworkSite

lib/towerops_web/live/org/gaiia_reconciliation_live.ex

@@ -129,18 +129,19 @@ defmodule ToweropsWeb.Org.GaiiaReconciliationLive do
      )}
   end
 
-  defp match_flash({:ok, 0, 0, _remaining}) do
+  defp match_flash({:ok, 0, 0, 0, _remaining}) do
     t("No matches found. Link devices manually on the mapping page.")
   end
 
-  defp match_flash({:ok, ip_matched, site_matched, remaining}) do
-    total = ip_matched + site_matched
+  defp match_flash({:ok, mac_matched, ip_matched, site_matched, remaining}) do
+    total = mac_matched + ip_matched + site_matched
 
     ngettext(
-      "Auto-matched %{total} device (%{ip} by IP, %{site} by site). %{remaining} remaining.",
-      "Auto-matched %{total} devices (%{ip} by IP, %{site} by site). %{remaining} remaining.",
+      "Auto-matched %{total} device (%{mac} by MAC, %{ip} by IP, %{site} by site). %{remaining} remaining.",
+      "Auto-matched %{total} devices (%{mac} by MAC, %{ip} by IP, %{site} by site). %{remaining} remaining.",
       total,
       total: total,
+      mac: mac_matched,
       ip: ip_matched,
       site: site_matched,
       remaining: remaining