diff --git a/test/aprsme/device_cache_test.exs b/test/aprsme/device_cache_test.exs
index 58e88fd..9de18a5 100644
--- a/test/aprsme/device_cache_test.exs
+++ b/test/aprsme/device_cache_test.exs
@@ -72,4 +72,32 @@ defmodule Aprsme.DeviceCacheTest do
       assert DeviceCache.lookup_device("APSXX") == nil
     end
   end
+
+  describe "GenServer callbacks" do
+    test "init/1 schedules an initial load and returns an empty state" do
+      assert {:ok, state} = DeviceCache.init([])
+      assert state == %{initial_load_done: false}
+      assert_receive :initial_load, 1_500
+    end
+
+    test "handle_call(:refresh_cache, _, state) returns :ok" do
+      state = %{initial_load_done: true}
+      assert {:reply, :ok, ^state} = DeviceCache.handle_call(:refresh_cache, self(), state)
+    end
+
+    test "handle_cast(:refresh_cache_async, state) keeps the state" do
+      state = %{initial_load_done: true}
+      assert {:noreply, ^state} = DeviceCache.handle_cast(:refresh_cache_async, state)
+    end
+
+    test "handle_info(:initial_load, state) flips initial_load_done and schedules a periodic refresh" do
+      assert {:noreply, %{initial_load_done: true}} =
+               DeviceCache.handle_info(:initial_load, %{initial_load_done: false})
+    end
+
+    test "handle_info(:refresh_cache, state) keeps the state and schedules a periodic refresh" do
+      state = %{initial_load_done: true}
+      assert {:noreply, ^state} = DeviceCache.handle_info(:refresh_cache, state)
+    end
+  end
 end
diff --git a/test/aprsme/device_identification_test.exs b/test/aprsme/device_identification_test.exs
index 8dd7c72..96ab201 100644
--- a/test/aprsme/device_identification_test.exs
+++ b/test/aprsme/device_identification_test.exs
@@ -148,6 +148,59 @@ defmodule Aprsme.DeviceIdentificationTest do
 
       assert :ok == DeviceIdentification.maybe_refresh_devices()
     end
+
+    test "attempts to refresh when there are no devices at all" do
+      Repo.delete_all(Devices)
+      # fetch_and_upsert_devices goes through the circuit breaker. Without a
+      # stub it either errors out (network failure) or returns :ok. Either
+      # outcome exercises the refresh_if_stale(nil, _) branch.
+      result = DeviceIdentification.maybe_refresh_devices()
+      assert result == :ok or match?({:error, _}, result)
+    end
+  end
+
+  describe "lookup_device_by_identifier/1 wildcard and escape handling" do
+    test "matches with a multi-character ? wildcard pattern" do
+      Repo.delete_all(Devices)
+
+      Repo.insert!(%Devices{
+        identifier: "APS???",
+        vendor: "TestVendor",
+        model: "TestModel"
+      })
+
+      devices = Repo.all(Devices)
+      Aprsme.Cache.put(:device_cache, :all_devices, devices)
+
+      # 'APSK21' has 6 characters, matching 'APS???'.
+      assert %Devices{identifier: "APS???"} = DeviceIdentification.lookup_device_by_identifier("APSK21")
+      # 'APS' alone is too short.
+      refute DeviceIdentification.lookup_device_by_identifier("APS")
+      # Different prefix should not match.
+      refute DeviceIdentification.lookup_device_by_identifier("ZZZK21")
+    end
+
+    test "patterns with regex metacharacters are escaped properly" do
+      Repo.delete_all(Devices)
+
+      Repo.insert!(%Devices{
+        identifier: "A.B+C*",
+        vendor: "Regex",
+        model: "Edge"
+      })
+
+      devices = Repo.all(Devices)
+      Aprsme.Cache.put(:device_cache, :all_devices, devices)
+
+      # The dot/plus/star should be treated as literals (no ? in pattern
+      # means exact match is used).
+      assert %Devices{identifier: "A.B+C*"} =
+               DeviceIdentification.lookup_device_by_identifier("A.B+C*")
+
+      # A string that would "match" if dot/plus/star were regex metachars
+      # must NOT match — they're literals.
+      refute DeviceIdentification.lookup_device_by_identifier("AXBCC")
+    end
   end
 
   describe "lookup_device_by_identifier/1" do
diff --git a/test/aprsme/signal_handler_test.exs b/test/aprsme/signal_handler_test.exs
index e2c6732..b639baa 100644
--- a/test/aprsme/signal_handler_test.exs
+++ b/test/aprsme/signal_handler_test.exs
@@ -13,4 +13,12 @@ defmodule Aprsme.SignalHandlerTest do
     # We can't safely exercise the :sigterm clause here — it calls
     # Aprsme.ShutdownHandler.shutdown() which would actually shut the app down.
   end
+
+  describe "init/1" do
+    test "installs a SIGTERM handler and returns an empty state" do
+      # :os.set_signal is process-global but calling it a second time with
+      # :handle is idempotent at the VM level. Safe to exercise.
+      assert {:ok, %{}} = SignalHandler.init([])
+    end
+  end
 end
diff --git a/test/aprsme_web/components/layouts_test.exs b/test/aprsme_web/components/layouts_test.exs
index f07799e..4ff3f66 100644
--- a/test/aprsme_web/components/layouts_test.exs
+++ b/test/aprsme_web/components/layouts_test.exs
@@ -1,6 +1,8 @@
 defmodule AprsmeWeb.LayoutsTest do
   use ExUnit.Case, async: true
 
+  import Phoenix.LiveViewTest
+
   alias AprsmeWeb.Layouts
 
   describe "body_class/1" do
@@ -20,4 +22,50 @@ defmodule AprsmeWeb.LayoutsTest do
       assert Layouts.body_class(%{whatever: 42}) == Layouts.body_class(%{})
     end
   end
+
+  describe "app/1 template" do
+    test "renders the site header and inner content" do
+      html =
+        render_component(&Layouts.app/1, %{
+          current_user: nil,
+          flash: %{},
+          map_page: false,
+          inner_content: Phoenix.HTML.raw("<p>inner-content-marker</p>")
+        })
+
+      assert html =~ "aprs.me"
+      assert html =~ "inner-content-marker"
+      # Default map_page is false, so data-map-page="false" is emitted.
+      assert html =~ ~s(data-map-page="false")
+    end
+
+    test "emits data-map-page=\"true\" for map pages" do
+      html =
+        render_component(&Layouts.app/1, %{
+          current_user: nil,
+          flash: %{},
+          map_page: true,
+          inner_content: Phoenix.HTML.raw("")
+        })
+
+      assert html =~ ~s(data-map-page="true")
+      assert html =~ "min-h-screen"
+    end
+  end
+
+  describe "root/1 template" do
+    test "renders the root layout with the inner content" do
+      html =
+        render_component(&Layouts.root/1, %{
+          current_user: nil,
+          inner_content: Phoenix.HTML.raw("<main>root-layout-marker</main>"),
+          conn: %Plug.Conn{},
+          page_title: nil
+        })
+
+      assert html =~ "root-layout-marker"
+      assert html =~ "<html"
+      assert html =~ "</html>"
+    end
+  end
 end
diff --git a/test/aprsme_web/controllers/user_session_controller_test.exs b/test/aprsme_web/controllers/user_session_controller_test.exs
new file mode 100644
index 0000000..0d85eb6
--- /dev/null
+++ b/test/aprsme_web/controllers/user_session_controller_test.exs
@@ -0,0 +1,106 @@
+defmodule AprsmeWeb.UserSessionControllerTest do
+  use AprsmeWeb.ConnCase
+
+  import Aprsme.AccountsFixtures
+
+  setup do
+    %{user: user_fixture()}
+  end
+
+  describe "POST /users/log_in" do
+    test "logs the user in", %{conn: conn, user: user} do
+      conn =
+        post(conn, ~p"/users/log_in", %{
+          "user" => %{"email" => user.email, "password" => valid_user_password()}
+        })
+
+      assert get_session(conn, :user_token)
+      assert redirected_to(conn) == ~p"/"
+    end
+
+    test "logs the user in with remember me", %{conn: conn, user: user} do
+      conn =
+        post(conn, ~p"/users/log_in", %{
+          "user" => %{
+            "email" => user.email,
+            "password" => valid_user_password(),
+            "remember_me" => "true"
+          }
+        })
+
+      assert conn.resp_cookies["_aprs_web_user_remember_me"]
+      assert redirected_to(conn) == ~p"/"
+    end
+
+    test "logs the user in with return to", %{conn: conn, user: user} do
+      conn =
+        conn
+        |> init_test_session(user_return_to: "/foo/bar")
+        |> post(~p"/users/log_in", %{
+          "user" => %{
+            "email" => user.email,
+            "password" => valid_user_password()
+          }
+        })
+
+      assert redirected_to(conn) == "/foo/bar"
+      assert Phoenix.Flash.get(conn.assigns.flash, :info) =~ "Welcome back!"
+    end
+
+    test "login following registration", %{conn: conn, user: user} do
+      conn =
+        post(conn, ~p"/users/log_in", %{
+          "_action" => "registered",
+          "user" => %{
+            "email" => user.email,
+            "password" => valid_user_password()
+          }
+        })
+
+      assert redirected_to(conn) == ~p"/"
+      assert Phoenix.Flash.get(conn.assigns.flash, :info) =~ "Account created successfully!"
+    end
+
+    test "login following password update", %{conn: conn, user: user} do
+      conn =
+        conn
+        |> init_test_session(%{})
+        |> post(~p"/users/log_in", %{
+          "_action" => "password_updated",
+          "user" => %{
+            "email" => user.email,
+            "password" => valid_user_password()
+          }
+        })
+
+      assert redirected_to(conn) == ~p"/users/settings"
+      assert Phoenix.Flash.get(conn.assigns.flash, :info) =~ "Password updated successfully!"
+    end
+
+    test "redirects to login page with invalid credentials", %{conn: conn, user: user} do
+      conn =
+        post(conn, ~p"/users/log_in", %{
+          "user" => %{"email" => user.email, "password" => "invalid_password"}
+        })
+
+      assert Phoenix.Flash.get(conn.assigns.flash, :error) == "Invalid email or password"
+      assert redirected_to(conn) == ~p"/users/log_in"
+    end
+  end
+
+  describe "DELETE /users/log_out" do
+    test "logs the user out", %{conn: conn, user: user} do
+      conn = conn |> log_in_user(user) |> delete(~p"/users/log_out")
+      assert redirected_to(conn) == ~p"/"
+      refute get_session(conn, :user_token)
+      assert Phoenix.Flash.get(conn.assigns.flash, :info) =~ "Logged out successfully"
+    end
+
+    test "succeeds even if the user is not logged in", %{conn: conn} do
+      conn = delete(conn, ~p"/users/log_out")
+      assert redirected_to(conn) == ~p"/"
+      refute get_session(conn, :user_token)
+      assert Phoenix.Flash.get(conn.assigns.flash, :info) =~ "Logged out successfully"
+    end
+  end
+end
diff --git a/test/aprsme_web/live/map_live/components_test.exs b/test/aprsme_web/live/map_live/components_test.exs
index 9d380c7..447122c 100644
--- a/test/aprsme_web/live/map_live/components_test.exs
+++ b/test/aprsme_web/live/map_live/components_test.exs
@@ -138,5 +138,76 @@ defmodule AprsmeWeb.MapLive.ComponentsTest do
       assert html =~ "All Packets"
       assert html =~ "With Position"
     end
+
+    test "renders packet cards for stations with positions" do
+      packet = %{
+        sender: "K5GVL-10",
+        ssid: "10",
+        lat: 33.1,
+        lon: -96.5,
+        has_position: true,
+        comment: "Mobile station",
+        path: "WIDE1-1",
+        received_at: DateTime.utc_now()
+      }
+
+      html =
+        render_component(
+          &Components.slideover_panel/1,
+          base_assigns(%{packets: [{"packet-1", packet}]})
+        )
+
+      assert html =~ "K5GVL-10"
+      assert html =~ "Mobile station"
+      # The center-on-packet button is rendered for packets with position.
+      assert html =~ "center_on_packet"
+    end
+
+    test "packet cards for stations without position hide the center button" do
+      packet = %{
+        sender: "K5GVL",
+        ssid: "0",
+        lat: nil,
+        lon: nil,
+        has_position: false,
+        comment: nil,
+        path: nil,
+        received_at: DateTime.utc_now()
+      }
+
+      html =
+        render_component(
+          &Components.slideover_panel/1,
+          base_assigns(%{packets: [{"packet-2", packet}]})
+        )
+
+      assert html =~ "K5GVL"
+      assert html =~ "direct"
+      refute html =~ "center_on_packet"
+    end
+
+    test "shows the last-seen timestamp for a tracked callsign" do
+      latest = %{received_at: DateTime.add(DateTime.utc_now(), -60, :second)}
+
+      html =
+        render_component(
+          &Components.slideover_panel/1,
+          base_assigns(%{
+            tracked_callsign: "K5ABC",
+            tracked_callsign_latest_packet: latest
+          })
+        )
+
+      assert html =~ "Last seen"
+    end
+  end
+
+  describe "map_styles/1" do
+    test "renders a <style> block" do
+      html = render_component(&Components.map_styles/1, %{})
+      assert html =~ "<style>"
+      assert html =~ "#aprs-map"
+      assert html =~ ".slideover-panel"
+    end
   end
 end
diff --git a/test/aprsme_web/live/map_live/packet_processor_test.exs b/test/aprsme_web/live/map_live/packet_processor_test.exs
index 9975d72..c869f3b 100644
--- a/test/aprsme_web/live/map_live/packet_processor_test.exs
+++ b/test/aprsme_web/live/map_live/packet_processor_test.exs
@@ -226,4 +226,40 @@ defmodule AprsmeWeb.MapLive.PacketProcessorTest do
       assert Map.has_key?(result.assigns.visible_packets, "OTHER-1")
     end
   end
+
+  describe "process_packet_for_display/2" do
+    test "updates last_update_at and returns {:noreply, socket}" do
+      socket = build_socket()
+      packet = build_packet()
+
+      before = DateTime.utc_now()
+      {:noreply, new_socket} = PacketProcessor.process_packet_for_display(packet, socket)
+
+      assert DateTime.compare(new_socket.assigns.last_update_at, before) in [:gt, :eq]
+      # Marker should have been added to visible_packets.
+      assert Map.has_key?(new_socket.assigns.visible_packets, "K5GVL-10")
+    end
+
+    test "leaves state mostly intact for out-of-bounds packets" do
+      socket = build_socket()
+      packet = build_packet(%{lat: 50.0, lon: -50.0})
+
+      {:noreply, new_socket} = PacketProcessor.process_packet_for_display(packet, socket)
+
+      refute Map.has_key?(new_socket.assigns.visible_packets, "K5GVL-10")
+      assert %DateTime{} = new_socket.assigns.last_update_at
+    end
+  end
+
+  describe "handle_valid_postgres_packet/4 at marker zoom" do
+    test "adds marker to visible_packets and returns a socket" do
+      socket = build_socket(%{map_zoom: 12})
+      packet = build_packet()
+
+      new_socket =
+        PacketProcessor.handle_valid_postgres_packet(packet, packet.lat, packet.lon, socket)
+
+      assert Map.has_key?(new_socket.assigns.visible_packets, "K5GVL-10")
+    end
+  end
 end