Refactor game mode scoring and win conditions

* Add overridable hooks for sunk/reaped ball handling and turn behavior.
* Implement default scoring and game-over messaging across game modes.
* Add pretty game mode names for win-condition messages.
* Update Free Ball, Last Ball, and Snooker modes to return win-condition messages.
* Move the reset button lookup to the scene root for multiplayer setup.
* Move camera controller scene to shared base UI. Move parts of it to new game_data UI node.
* Add commented test state generation for end-state testing.

scenes/ui_controls/game/data.tscn

@@ -0,0 +1,54 @@
+[gd_scene load_steps=3 format=3 uid="uid://l3bve6miq8od"]
+
+[ext_resource type="Script" uid="uid://br6jmlm4poh62" path="res://scenes/ui_controls/game/data.gd" id="1_s7215"]
+
+[sub_resource type="LabelSettings" id="LabelSettings_o1hjn"]
+font_color = Color(0, 1, 0.14117648, 1)
+
+[node name="data" type="Control"]
+layout_mode = 3
+anchors_preset = 10
+anchor_right = 1.0
+grow_horizontal = 2
+script = ExtResource("1_s7215")
+
+[node name="vbox" type="VBoxContainer" parent="."]
+layout_mode = 0
+offset_left = 10.0
+offset_top = 5.0
+offset_right = 1142.0
+offset_bottom = 69.0
+
+[node name="hbox" type="HBoxContainer" parent="vbox"]
+layout_mode = 2
+size_flags_vertical = 3
+
+[node name="hbox" type="HBoxContainer" parent="vbox/hbox"]
+layout_mode = 2
+size_flags_horizontal = 3
+
+[node name="player_lbl" type="Label" parent="vbox/hbox/hbox"]
+layout_mode = 2
+text = "Player 1"
+
+[node name="active_lbl" type="Label" parent="vbox/hbox/hbox"]
+visible = false
+layout_mode = 2
+text = "Active"
+label_settings = SubResource("LabelSettings_o1hjn")
+uppercase = true
+
+[node name="hbox2" type="HBoxContainer" parent="vbox/hbox"]
+layout_mode = 2
+size_flags_horizontal = 8
+size_flags_vertical = 3
+
+[node name="reset_bttn" type="Button" parent="vbox/hbox/hbox2"]
+layout_mode = 2
+focus_mode = 0
+mouse_default_cursor_shape = 2
+text = "Reset"
+flat = true
+alignment = 0
+
+[connection signal="pressed" from="vbox/hbox/hbox2/reset_bttn" to="." method="_on_reset_bttn_pressed"]