Game picker and save browser: menu window shell, background warm-up

The main menu warms every ready game's mods up into the assembly cache in the
background (last played first), so picking a game only loads cached assemblies.
Game picker and save browser are scenes on the shared MenuWindowShell (also used by
the settings): caps title, close on the right, footer hint; the picker footer shows
the warm-up state, cards get framed covers with a letter placeholder and Continue as
the main action; the save browser shows 3x2 large cards with the game selector in
the header. new_game waits for the warm-up; menu_flow takes --shots.

scenes/menu/save_load_menu.tscn

@@ -1,84 +1,131 @@
-[gd_scene load_steps=3 format=3]
+[gd_scene format=3]
 
 [ext_resource type="Script" path="src/SaveLoadMenu.cs" id="SaveLoadMenuScript"]
 [ext_resource type="Script" path="src/SaveSlotList.cs" id="SaveSlotListScript"]
 
-[node name="SaveLoadMenu" type="Control"]
+[node name="SaveLoadMenu" type="Control" unique_id=1300922993]
 layout_mode = 3
 anchors_preset = 15
 anchor_right = 1.0
 anchor_bottom = 1.0
 grow_horizontal = 2
 grow_vertical = 2
-mouse_filter = 1
 script = ExtResource("SaveLoadMenuScript")
 
-[node name="Bg" type="ColorRect" parent="."]
+[node name="Backdrop" type="ColorRect" parent="." unique_id=1957446002]
 layout_mode = 1
 anchors_preset = 15
 anchor_right = 1.0
 anchor_bottom = 1.0
 grow_horizontal = 2
 grow_vertical = 2
-color = Color(0, 0, 0, 0.65)
+color = Color(0, 0, 0, 0.9)
 
-[node name="Panel" type="Panel" parent="."]
+[node name="Window" type="PanelContainer" parent="." unique_id=1214442353]
 layout_mode = 1
 anchors_preset = 8
 anchor_left = 0.5
 anchor_top = 0.5
 anchor_right = 0.5
 anchor_bottom = 0.5
-offset_left = -420.0
-offset_top = -280.0
-offset_right = 420.0
-offset_bottom = 280.0
+offset_left = -500.0
+offset_top = -350.0
+offset_right = 500.0
+offset_bottom = 350.0
 grow_horizontal = 2
 grow_vertical = 2
 
-[node name="Margin" type="MarginContainer" parent="Panel"]
-layout_mode = 1
-anchors_preset = 15
-anchor_right = 1.0
-anchor_bottom = 1.0
-grow_horizontal = 2
-grow_vertical = 2
-theme_override_constants/margin_left = 28
-theme_override_constants/margin_top = 20
-theme_override_constants/margin_right = 28
-theme_override_constants/margin_bottom = 20
-
-[node name="VBox" type="VBoxContainer" parent="Panel/Margin"]
+[node name="Column" type="VBoxContainer" parent="Window" unique_id=154632647]
 layout_mode = 2
-theme_override_constants/separation = 14
+theme_override_constants/separation = 0
 
-[node name="Title" type="Label" parent="Panel/Margin/VBox"]
+[node name="Header" type="MarginContainer" parent="Window/Column" unique_id=255743212]
 layout_mode = 2
-text = "Save/Load"
-horizontal_alignment = 1
-theme_override_font_sizes/font_size = 24
+theme_override_constants/margin_left = 24
+theme_override_constants/margin_top = 16
+theme_override_constants/margin_right = 16
+theme_override_constants/margin_bottom = 16
 
-[node name="GameSelect" type="OptionButton" parent="Panel/Margin/VBox"]
+[node name="Row" type="HBoxContainer" parent="Window/Column/Header" unique_id=1566510433]
 layout_mode = 2
+theme_override_constants/separation = 24
 
-[node name="Scroll" type="ScrollContainer" parent="Panel/Margin/VBox"]
+[node name="Title" type="Label" parent="Window/Column/Header/Row" unique_id=1345868865]
+layout_mode = 2
+size_flags_vertical = 4
+text = "Load"
+uppercase = true
+
+[node name="GameSelect" type="OptionButton" parent="Window/Column/Header/Row" unique_id=1531297566]
+custom_minimum_size = Vector2(280, 0)
+layout_mode = 2
+size_flags_vertical = 4
+
+[node name="Spacer" type="Control" parent="Window/Column/Header/Row" unique_id=739525391]
 layout_mode = 2
 size_flags_horizontal = 3
+mouse_filter = 2
+
+[node name="CloseButton" type="Button" parent="Window/Column/Header/Row" unique_id=1063180782]
+layout_mode = 2
+custom_minimum_size = Vector2(38, 38)
+size_flags_vertical = 4
+focus_mode = 0
+text = "✕"
+
+[node name="RuleHeader" type="ColorRect" parent="Window/Column" unique_id=1844886327]
+custom_minimum_size = Vector2(0, 1)
+layout_mode = 2
+
+[node name="Body" type="MarginContainer" parent="Window/Column" unique_id=280231313]
+layout_mode = 2
+size_flags_vertical = 3
+theme_override_constants/margin_left = 24
+theme_override_constants/margin_top = 20
+theme_override_constants/margin_right = 24
+theme_override_constants/margin_bottom = 20
+
+[node name="Content" type="VBoxContainer" parent="Window/Column/Body" unique_id=1998936353]
+layout_mode = 2
+theme_override_constants/separation = 12
+
+[node name="Scroll" type="ScrollContainer" parent="Window/Column/Body/Content" unique_id=131125275]
+layout_mode = 2
 size_flags_vertical = 3
-custom_minimum_size = Vector2(0, 380)
 horizontal_scroll_mode = 0
 
-[node name="SlotGrid" type="Control" parent="Panel/Margin/VBox/Scroll"]
+[node name="SlotGrid" type="Control" parent="Window/Column/Body/Content/Scroll" unique_id=702369365]
 layout_mode = 2
 size_flags_horizontal = 3
 script = ExtResource("SaveSlotListScript")
+ColumnCount = 3
+RowCount = 2
+SlotPadding = 14.0
 
-[node name="EmptyLabel" type="Label" parent="Panel/Margin/VBox"]
+[node name="EmptyLabel" type="Label" parent="Window/Column/Body/Content" unique_id=1909778806]
 layout_mode = 2
+size_flags_vertical = 3
 horizontal_alignment = 1
+vertical_alignment = 1
 visible = false
 
-[node name="BackBtn" type="Button" parent="Panel/Margin/VBox"]
+[node name="RuleFooter" type="ColorRect" parent="Window/Column" unique_id=225368463]
+custom_minimum_size = Vector2(0, 1)
 layout_mode = 2
-text = "Back"
-size_flags_horizontal = 8
+
+[node name="Footer" type="MarginContainer" parent="Window/Column" unique_id=775810662]
+layout_mode = 2
+theme_override_constants/margin_left = 24
+theme_override_constants/margin_top = 12
+theme_override_constants/margin_right = 24
+theme_override_constants/margin_bottom = 12
+
+[node name="Row" type="HBoxContainer" parent="Window/Column/Footer" unique_id=1592632905]
+custom_minimum_size = Vector2(0, 38)
+layout_mode = 2
+theme_override_constants/separation = 12
+
+[node name="Hint" type="Label" parent="Window/Column/Footer/Row" unique_id=1935428591]
+layout_mode = 2
+size_flags_horizontal = 3
+size_flags_vertical = 4