Quaternius weapons, input fixes, sound & path fixes

- Added 6 Quaternius weapon models (Pistol, Revolver, Rifle, Shotgun, P90, SniperRifle)
- Created weapon resource files with balanced stats
- Wired Pistol + Rifle into player.tscn replacing Kenney blasters
- Fixed WASD input (matched input map action names)
- Fixed Escape key toggles mouse capture
- Added Audio autoload singleton
- Fixed broken sound asset paths across all scripts
- Fixed all scene ext_resource text paths (nested under assets/kenney-fps/)
- Fixed all .import source_file paths
- Deleted stale .import files (will be regenerated by editor on open)

assets/kenney-fps/fonts/lilita_one_regular.ttf.import

@@ -1,36 +0,0 @@
-[remap]
-
-importer="font_data_dynamic"
-type="FontFile"
-uid="uid://biqtga8moh7ah"
-path="res://.godot/imported/lilita_one_regular.ttf-68cc4ab6825bdd499d1ad608190f5213.fontdata"
-
-[deps]
-
-source_file="res://fonts/lilita_one_regular.ttf"
-dest_files=["res://.godot/imported/lilita_one_regular.ttf-68cc4ab6825bdd499d1ad608190f5213.fontdata"]
-
-[params]
-
-Rendering=null
-antialiasing=1
-generate_mipmaps=false
-disable_embedded_bitmaps=true
-multichannel_signed_distance_field=false
-msdf_pixel_range=8
-msdf_size=48
-allow_system_fallback=true
-force_autohinter=false
-modulate_color_glyphs=false
-hinting=1
-subpixel_positioning=1
-keep_rounding_remainders=true
-oversampling=0.0
-Fallbacks=null
-fallbacks=[]
-Compress=null
-compress=true
-preload=[]
-language_support={}
-script_support={}
-opentype_features={}