fix(rover-planning): suppress fresh-station error + tolerate integer JSONB values

- add_station no longer seeds `"input" => ""` in params, so used_input?/1
  treats the new row as untouched and hides the validate_required error
  until the user types.
- Show page's format_distance/format_db/format_meters helpers coerce with
  `* 1.0` because JSONB returns bare zeros as integers, which crashed
  Float.round/2 (FunctionClauseError on /rover-planning/:id render).
- Lat/lon row uses items-start + mt-6 trash so the inputs stay aligned
  even when the callsign cell grows from validation feedback.

lib/microwaveprop_web/live/rover_planning_live/form.ex

@@ -91,9 +91,12 @@ defmodule MicrowavepropWeb.RoverPlanningLive.Form do
     stations = Map.get(params, "stations", %{})
     next_index = next_station_index(stations)
 
+    # Don't include "input" in the new station's params — `used_input?/1`
+    # treats any field present in params as "used" and would render the
+    # `validate_required([:input])` error before the user has typed
+    # anything. Leaving the key out keeps the row pristine until edited.
     stations =
       Map.put(stations, Integer.to_string(next_index), %{
-        "input" => "",
         "position" => Integer.to_string(next_index)
       })
 
@@ -247,14 +250,20 @@ defmodule MicrowavepropWeb.RoverPlanningLive.Form do
 
           <.inputs_for :let={s} field={@form[:stations]}>
             <div class="card bg-base-200 p-3 mb-2">
-              <div class="grid grid-cols-1 md:grid-cols-2 gap-2">
+              <%!--
+                `items-start` keeps the lat/lon row top-aligned even when the
+                callsign cell grows (e.g. an error message under the input).
+                The trash button uses `mt-6` to sit beside the input — matches
+                the label height so it visually aligns with the input field.
+              --%>
+              <div class="grid grid-cols-1 md:grid-cols-2 gap-2 items-start">
                 <.input
                   field={s[:input]}
                   type="text"
                   label="Callsign / grid / lat,lon"
                   placeholder="W5LUA or EM13qc or 32.91, -97.06"
                 />
-                <div class="flex items-end gap-2">
+                <div class="flex items-start gap-2">
                   <div class="flex-1">
                     <.input field={s[:lat]} type="number" step="any" label="Lat" />
                   </div>
@@ -265,7 +274,7 @@ defmodule MicrowavepropWeb.RoverPlanningLive.Form do
                     type="button"
                     phx-click="remove_station"
                     phx-value-index={s.index}
-                    class="btn btn-ghost btn-sm text-error mb-2"
+                    class="btn btn-ghost btn-sm text-error mt-6"
                     title="Remove station"
                   >
                     <.icon name="hero-trash" class="w-4 h-4" />

lib/microwaveprop_web/live/rover_planning_live/show.ex

@@ -124,12 +124,18 @@ defmodule MicrowavepropWeb.RoverPlanningLive.Show do
     %{total: total, complete: complete, pending: pending, failed: failed}
   end
 
-  defp format_distance(km) when is_number(km), do: "#{Float.round(km, 1)} km / #{Float.round(km * 0.621371, 1)} mi"
+  # JSONB round-trips bare zeros as integers (e.g. `0` not `0.0`), and
+  # `Float.round/2` only accepts floats. Coerce with `* 1.0` everywhere
+  # we round a value that came out of a `:map` column.
+  defp format_distance(km) when is_number(km), do: "#{Float.round(km * 1.0, 1)} km / #{Float.round(km * 0.621371, 1)} mi"
 
   defp format_distance(_), do: "—"
 
   defp format_db(nil), do: "—"
-  defp format_db(value) when is_number(value), do: "#{Float.round(value, 1)} dB"
+  defp format_db(value) when is_number(value), do: "#{Float.round(value * 1.0, 1)} dB"
+
+  defp format_meters(nil), do: "—"
+  defp format_meters(value) when is_number(value), do: "#{Float.round(value * 1.0, 1)} m"
 
   defp rover_label(%{rover_location: %{lat: lat, lon: lon}}) when is_number(lat) and is_number(lon) do
     grid = Maidenhead.from_latlon(lat, lon, 6)
@@ -243,9 +249,7 @@ defmodule MicrowavepropWeb.RoverPlanningLive.Show do
                   {if path.result, do: format_distance(path.result["distance_km"]), else: "—"}
                 </td>
                 <td class="text-xs">
-                  {if path.result,
-                    do: "#{Float.round(path.result["min_clearance_m"] || 0.0, 1)} m",
-                    else: "—"}
+                  {if path.result, do: format_meters(path.result["min_clearance_m"]), else: "—"}
                 </td>
                 <td class="text-xs">
                   {if path.result, do: format_db(path.result["diffraction_db"]), else: "—"}

test/microwaveprop_web/live/rover_planning_live_test.exs

@@ -4,8 +4,10 @@ defmodule MicrowavepropWeb.RoverPlanningLiveTest do
   import Phoenix.LiveViewTest
 
   alias Microwaveprop.AccountsFixtures
+  alias Microwaveprop.Repo
   alias Microwaveprop.Rover
   alias Microwaveprop.RoverPlanning
+  alias Microwaveprop.RoverPlanning.Path
   alias Microwaveprop.Terrain.ElevationClient
 
   setup do
@@ -69,6 +71,34 @@ defmodule MicrowavepropWeb.RoverPlanningLiveTest do
       assert html =~ "Path profiles"
     end
 
+    test "renders integer path-result values without crashing", %{conn: conn} do
+      # JSONB round-trips bare zeros as integers (e.g. `0` not `0.0`), so the
+      # show page MUST tolerate non-float numerics in `result`. Previously
+      # `Float.round(value, n)` crashed with FunctionClauseError when value
+      # came back as integer 0.
+      user = AccountsFixtures.user_fixture()
+      mission = create_mission(user, "Integer result mission")
+
+      [path | _] = Repo.all(Path)
+
+      {:ok, _} =
+        path
+        |> Ecto.Changeset.change(%{
+          status: :complete,
+          result: %{
+            "distance_km" => 0,
+            "min_clearance_m" => 0,
+            "diffraction_db" => 0,
+            "verdict" => "clear"
+          }
+        })
+        |> Repo.update()
+
+      {:ok, _lv, html} = live(conn, ~p"/rover-planning/#{mission.id}")
+      assert html =~ "Integer result mission"
+      assert html =~ "Clear"
+    end
+
     test "redirects when mission missing", %{conn: conn} do
       missing = Ecto.UUID.generate()
 
@@ -83,6 +113,21 @@ defmodule MicrowavepropWeb.RoverPlanningLiveTest do
                live(conn, ~p"/rover-planning/new")
     end
 
+    test "clicking 'Add station' does not show 'can't be blank' on the new row", %{conn: conn} do
+      user = AccountsFixtures.user_fixture()
+      conn = log_in_user(conn, user)
+      {:ok, lv, _html} = live(conn, ~p"/rover-planning/new")
+
+      html =
+        lv
+        |> element("button[phx-click='add_station']")
+        |> render_click()
+
+      # The new (untouched) station must not render a validation error until
+      # the user actually interacts with its input.
+      refute html =~ "can't be blank"
+    end
+
     test "typing into the form does not flip the only_known_good checkbox", %{conn: conn} do
       user = AccountsFixtures.user_fixture()
       conn = log_in_user(conn, user)