Add split-screen Space Shooter with pod steering and boost.

Two-player mode with client assignment, 3D vector calibration for cylindrical
pods, lives, tap/double-tap boost with low-intensity LED cooldown feedback,
and Kenney sprite assets.

Co-authored-by: Cursor <cursoragent@cursor.com>

assets/Bonus/sfx_shieldDown.ogg.import

@@ -0,0 +1,19 @@
+[remap]
+
+importer="oggvorbisstr"
+type="AudioStreamOggVorbis"
+uid="uid://d018uhp2lopms"
+path="res://.godot/imported/sfx_shieldDown.ogg-e123a09673f077c9bca6b2db114368c4.oggvorbisstr"
+
+[deps]
+
+source_file="res://assets/Bonus/sfx_shieldDown.ogg"
+dest_files=["res://.godot/imported/sfx_shieldDown.ogg-e123a09673f077c9bca6b2db114368c4.oggvorbisstr"]
+
+[params]
+
+loop=false
+loop_offset=0
+bpm=0
+beat_count=0
+bar_beats=4