refactor: DRY extract_bearer, reuse validation helpers, add query limits

- Extract shared extract_bearer/1 from api/monitor_auth.ex → api/auth.ex
- Refactor admin_changeset to pipeline through validate_callsign/validate_name/validate_email
- Add limit: 500 to list_beacons/0 and candidate_rover_locations/1
- Combine get_mission_with_paths preloads into single round-trip

lib/microwaveprop/accounts/user.ex

@@ -82,15 +82,9 @@ defmodule Microwaveprop.Accounts.User do
     user
     |> cast(attrs, [:callsign, :name, :email, :is_admin])
     |> update_change(:callsign, fn cs -> cs && cs |> String.trim() |> String.upcase() end)
-    |> validate_required([:callsign, :name, :email])
-    |> validate_format(:callsign, ~r/^[A-Z0-9]{3,10}$/, message: "must be 3-10 letters and digits")
-    |> validate_length(:name, min: 1, max: 100)
-    |> validate_format(:email, ~r/^[^@,;\s]+@[^@,;\s]+$/, message: "must have the @ sign and no spaces")
-    |> validate_length(:email, max: 160)
-    |> unsafe_validate_unique(:callsign, Microwaveprop.Repo)
-    |> unique_constraint(:callsign)
-    |> unsafe_validate_unique(:email, Microwaveprop.Repo)
-    |> unique_constraint(:email)
+    |> validate_callsign([])
+    |> validate_name()
+    |> validate_email([])
   end
 
   defp validate_callsign(changeset, opts) do

lib/microwaveprop/beacons.ex

@@ -35,7 +35,8 @@ defmodule Microwaveprop.Beacons do
     Repo.all(
       from b in Beacon,
         where: b.approved == true,
-        order_by: [desc: b.inserted_at]
+        order_by: [desc: b.inserted_at],
+        limit: 500
     )
   end
 

lib/microwaveprop/rover_planning.ex

@@ -45,9 +45,14 @@ defmodule Microwaveprop.RoverPlanning do
 
   @spec get_mission_with_paths(Ecto.UUID.t()) :: Mission.t() | nil | [%{atom() => any()}]
   def get_mission_with_paths(id) do
-    case get_mission(id) do
-      nil -> nil
-      mission -> Repo.preload(mission, paths: [:rover_location, :station])
+    case Ecto.UUID.cast(id) do
+      {:ok, uuid} ->
+        Mission
+        |> Repo.get(uuid)
+        |> Repo.preload([:user, stations: from(s in Station, order_by: s.position), paths: [:rover_location, :station]])
+
+      :error ->
+        nil
     end
   end
 
@@ -245,11 +250,11 @@ defmodule Microwaveprop.RoverPlanning do
   """
   @spec candidate_rover_locations(Mission.t()) :: [Location.t()]
   def candidate_rover_locations(%Mission{only_known_good: true}) do
-    Repo.all(from(l in Location, where: l.status == :good, order_by: [desc: l.inserted_at]))
+    Repo.all(from(l in Location, where: l.status == :good, order_by: [desc: l.inserted_at], limit: 500))
   end
 
   def candidate_rover_locations(%Mission{only_known_good: false}) do
-    Repo.all(from(l in Location, order_by: [desc: l.inserted_at]))
+    Repo.all(from(l in Location, order_by: [desc: l.inserted_at], limit: 500))
   end
 
   defp insert_pending_paths_and_jobs([], _mission), do: :ok

lib/microwaveprop_web/api/auth.ex

@@ -68,7 +68,9 @@ defmodule MicrowavepropWeb.Api.Auth do
     end
   end
 
-  defp extract_bearer(conn) do
+  @doc false
+  @spec extract_bearer(Plug.Conn.t()) :: {:ok, String.t()} | {:error, :missing_token | :invalid_authorization_header}
+  def extract_bearer(conn) do
     case get_req_header(conn, "authorization") do
       ["Bearer " <> token] when byte_size(token) > 0 -> {:ok, token}
       ["bearer " <> token] when byte_size(token) > 0 -> {:ok, token}

lib/microwaveprop_web/api/monitor_auth.ex

@@ -22,6 +22,7 @@ defmodule MicrowavepropWeb.Api.MonitorAuth do
   import Plug.Conn
 
   alias Microwaveprop.BeaconMonitors
+  alias MicrowavepropWeb.Api.Auth
   alias MicrowavepropWeb.Api.ErrorJSON
 
   @impl true
@@ -44,14 +45,7 @@ defmodule MicrowavepropWeb.Api.MonitorAuth do
     end
   end
 
-  defp extract_bearer(conn) do
-    case get_req_header(conn, "authorization") do
-      ["Bearer " <> token] when byte_size(token) > 0 -> {:ok, token}
-      ["bearer " <> token] when byte_size(token) > 0 -> {:ok, token}
-      [] -> {:error, :missing_token}
-      _ -> {:error, :invalid_authorization_header}
-    end
-  end
+  defp extract_bearer(conn), do: Auth.extract_bearer(conn)
 
   defp assign_monitor(conn, monitor) do
     # The rate-limiter buckets on `current_api_token.id`. Map the