fix(rover-planning): index 'Band' column shows all mission bands

The /rover-planning index was rendering only band_mhz (the legacy
primary single-band column), so multi-band missions with bands_mhz
populated showed just the first band. Switched the renderer to
arity-2 and now pulls the full bands list via Mission.bands/1, so
multi-band missions render '10 GHz · 24 GHz · 47 GHz' etc. Sort
still keys on band_mhz so the column stays sortable on a single
scalar value.

lib/microwaveprop_web/live/rover_planning_live.ex

@@ -8,6 +8,7 @@ defmodule MicrowavepropWeb.RoverPlanningLive do
 
   alias Microwaveprop.Accounts.User
   alias Microwaveprop.RoverPlanning
+  alias Microwaveprop.RoverPlanning.Mission
 
   def table_options do
     %{sorting: %{default_sort: [inserted_at: :desc]}}
@@ -18,7 +19,7 @@ defmodule MicrowavepropWeb.RoverPlanningLive do
       id: %{label: "ID", hidden: true},
       user_id: %{label: "Owner", hidden: true},
       name: %{label: "Mission", sortable: true, searchable: true, renderer: &name_cell/2},
-      band_mhz: %{label: "Band", sortable: true, renderer: &band_cell/1},
+      band_mhz: %{label: "Bands", sortable: true, renderer: &bands_cell/2},
       only_known_good: %{label: "Scope", sortable: true, renderer: &scope_cell/1},
       inserted_at: %{label: "Created", sortable: true, renderer: &format_ts/1}
     ]
@@ -136,18 +137,26 @@ defmodule MicrowavepropWeb.RoverPlanningLive do
     """
   end
 
-  defp band_cell(nil), do: "—"
+  # Renders the full bands list (multi-band missions can have several;
-
+  # the bound column is `band_mhz` so the table can still sort by the
-  defp band_cell(mhz) when is_integer(mhz) do
+  # primary band, but the cell shows every band the matrix scores).
-    if mhz >= 1000 do
+  defp bands_cell(_value, record) do
-      ghz = mhz / 1000
+    case Mission.bands(struct(Mission, Map.take(record, [:band_mhz, :bands_mhz]))) do
-      label = if ghz == trunc(ghz), do: "#{trunc(ghz)}", else: Float.to_string(Float.round(ghz, 1))
+      [] -> "—"
-      "#{label} GHz"
+      [single] -> band_label(single)
-    else
+      list -> Enum.map_join(list, " · ", &band_label/1)
-      "#{mhz} MHz"
     end
   end
 
+  defp band_label(mhz) when is_integer(mhz) and mhz >= 1000 do
+    ghz = mhz / 1000
+    label = if ghz == trunc(ghz), do: "#{trunc(ghz)}", else: Float.to_string(Float.round(ghz, 1))
+    "#{label} GHz"
+  end
+
+  defp band_label(mhz) when is_integer(mhz), do: "#{mhz} MHz"
+  defp band_label(_), do: "—"
+
   defp scope_cell(true) do
     assigns = %{}
     ~H|<span class="badge badge-success badge-sm">Known good only</span>|