perf: fix high-severity LiveView blocking queries

- rover_planning_live/show.ex: use pre-loaded @rover_sites assign
  instead of Repo.all(Location) on every keystroke
- rover_locations_live/map.ex: cache locations query with 30s TTL
  (was loading + JSON-encoding all good locations in every mount)
- status_live.ex: consolidate 5 separate stat fetches into single
  cached blob, so PubSub-triggered refreshes hit cache instead of
  running 10+ DB queries each time

lib/microwaveprop_web/live/rover_locations_live/map.ex

@@ -7,17 +7,17 @@ defmodule MicrowavepropWeb.RoverLocationsLive.Map do
 
   import Ecto.Query
 
+  alias Microwaveprop.Cache
   alias Microwaveprop.Radio.Maidenhead
   alias Microwaveprop.Repo
   alias Microwaveprop.Rover.Location
 
+  @cache_key {__MODULE__, :points}
+  @cache_ttl_ms 30_000
+
   @impl true
   def mount(_params, _session, socket) do
-    points =
-      Location
-      |> where([l], l.status == :good)
-      |> Repo.all()
-      |> Enum.map(&point_payload/1)
+    points = cached_points()
 
     {:ok,
      assign(socket,
@@ -27,6 +27,15 @@ defmodule MicrowavepropWeb.RoverLocationsLive.Map do
      )}
   end
 
+  defp cached_points do
+    Cache.fetch_or_store(@cache_key, @cache_ttl_ms, fn ->
+      Location
+      |> where([l], l.status == :good)
+      |> Repo.all()
+      |> Enum.map(&point_payload/1)
+    end)
+  end
+
   defp point_payload(%Location{} = loc) do
     %{
       id: loc.id,

lib/microwaveprop_web/live/rover_planning_live/show.ex

@@ -51,7 +51,7 @@ defmodule MicrowavepropWeb.RoverPlanningLive.Show do
     {:noreply,
      assign(socket,
        rover_site_input: input,
-       rover_site_input_matches: find_grid_matches(input)
+       rover_site_input_matches: find_grid_matches(input, socket.assigns.rover_sites)
      )}
   end
 
@@ -112,20 +112,14 @@ defmodule MicrowavepropWeb.RoverPlanningLive.Show do
 
   defp authenticated(_), do: {:error, :unauthenticated}
 
-  # Resolve the user-typed input and surface any existing rover-locations
-  # that share its 6-char Maidenhead grid (sub-grid resolution ≈ 5 km).
-  # Cheap enough for ~hundreds of locations: we map them in memory rather
-  # than maintaining a stored grid column.
-  defp find_grid_matches(input) when is_binary(input) do
+  defp find_grid_matches(input, locations) when is_binary(input) do
     trimmed = String.trim(input)
 
     case trimmed != "" && LocationResolver.resolve(trimmed) do
       {:ok, %{lat: lat, lon: lon}} when is_number(lat) and is_number(lon) ->
         target = Maidenhead.from_latlon(lat, lon, 6)
 
-        Location
-        |> Repo.all()
-        |> Enum.filter(fn loc ->
+        Enum.filter(locations, fn loc ->
           Maidenhead.from_latlon(loc.lat, loc.lon, 6) == target
         end)
 
@@ -134,7 +128,7 @@ defmodule MicrowavepropWeb.RoverPlanningLive.Show do
     end
   end
 
-  defp find_grid_matches(_), do: []
+  defp find_grid_matches(_, _), do: []
 
   defp can_modify?(%{current_scope: %{user: %User{is_admin: true}}}, _), do: true
 

lib/microwaveprop_web/live/status_live.ex

@@ -10,6 +10,9 @@ defmodule MicrowavepropWeb.StatusLive do
   alias Microwaveprop.Repo
   alias Microwaveprop.Weather.NarrClient
 
+  @all_stats_cache_key {__MODULE__, :all_stats}
+  @stats_cache_ttl_ms 2_000
+
   @impl true
   def mount(_params, _session, socket) do
     _ =
@@ -19,24 +22,20 @@ defmodule MicrowavepropWeb.StatusLive do
         # Rust prop-grid-rs emits NOTIFY propagation_ready on completion —
         # PropagationNotifyListener fans it out as `propagation:updated` so
         # the grid_tasks panel transitions from "running" → "done" without
-        # a manual refresh.
+        # a single refresh.
         Phoenix.PubSub.subscribe(Microwaveprop.PubSub, "propagation:updated")
       end
 
-    stats = fetch_stats()
-    unprocessed = count_unprocessed()
-    db_stats = fetch_db_stats()
-    grid_tasks = fetch_grid_tasks_stats()
-    hrrr_point_tasks = fetch_hrrr_point_tasks_stats()
+    all = fetch_all_stats()
 
     {:ok,
      assign(socket,
        page_title: "Status",
-       stats: stats,
-       unprocessed: unprocessed,
-       db_stats: db_stats,
-       grid_tasks: grid_tasks,
-       hrrr_point_tasks: hrrr_point_tasks,
+       stats: all.stats,
+       unprocessed: all.unprocessed,
+       db_stats: all.db_stats,
+       grid_tasks: all.grid_tasks,
+       hrrr_point_tasks: all.hrrr_point_tasks,
        refresh_timer: nil
      )}
   end
@@ -55,25 +54,36 @@ defmodule MicrowavepropWeb.StatusLive do
   end
 
   def handle_info(:refresh_stats, socket) do
+    all = fetch_all_stats()
+
     {:noreply,
      assign(socket,
-       stats: fetch_stats(),
-       unprocessed: count_unprocessed(),
-       db_stats: fetch_db_stats(),
-       grid_tasks: fetch_grid_tasks_stats(),
-       hrrr_point_tasks: fetch_hrrr_point_tasks_stats(),
+       stats: all.stats,
+       unprocessed: all.unprocessed,
+       db_stats: all.db_stats,
+       grid_tasks: all.grid_tasks,
+       hrrr_point_tasks: all.hrrr_point_tasks,
        refresh_timer: nil
      )}
   end
 
+  defp fetch_all_stats do
+    Cache.fetch_or_store(@all_stats_cache_key, @stats_cache_ttl_ms, fn ->
+      %{
+        stats: fetch_stats(),
+        unprocessed: count_unprocessed(),
+        db_stats: fetch_db_stats(),
+        grid_tasks: fetch_grid_tasks_stats(),
+        hrrr_point_tasks: fetch_hrrr_point_tasks_stats()
+      }
+    end)
+  end
+
   defp schedule_refresh(%{assigns: %{refresh_timer: ref}} = socket) when is_reference(ref) do
-    # Already scheduled, skip
     socket
   end
 
   defp schedule_refresh(socket) do
-    # 2s debounce — bulk enrichment runs produce hundreds of status_changed
-    # events per second, and each stats refresh fires 8+ count queries.
     ref = Process.send_after(self(), :refresh_stats, 2_000)
     assign(socket, refresh_timer: ref)
   end