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)

examples/multiplayer-fps/scripts/player.gd

@@ -133,7 +133,14 @@ func _process(_delta: float):
 	if _is_local and input:
 		var mx := Input.get_axis("move_west", "move_east")
 		var mz := Input.get_axis("move_north", "move_south")
-		get_window().title = "TS [mv=%.1f,%.1f] [sl=%s%s%s%s] [fire=%s]" % [mx, mz, input.slot_1, input.slot_2, input.slot_3, input.slot_4, input.fire_held]
+		var dead := death_tick >= 0
+		var frozen := round_manager != null and round_manager.freeze_end_tick >= 0 and NetworkTime.tick < round_manager.freeze_end_tick
+		var hp_str := str(health)
+		var rm_ok := round_manager != null
+		# Weapon model load status from weapon_manager
+		var knife_ok := weapon_manager != null and weapon_manager.has_knife_model()
+		var gun_ok := weapon_manager != null and weapon_manager.has_gun_model()
+		get_window().title = "TS [mv=%.1f,%.1f] hp=%s d=%s f=%s k=%s g=%s [fire=%s]" % [mx, mz, hp_str, dead, frozen, knife_ok, gun_ok, input.fire_held]
 	
 	# Smooth position interpolation between ticks
 	var f := NetworkTime.tick_factor