Reorganize the codebase into role-based folders (snake_case)

Move the 40-odd root-level scripts and scenes into a tree that groups by role,
per the approved roadmap (WS2/WS3): actors/{player,matador,bear}, systems/{combat,
fx,input,debug,render,crowd,config}, ui/, props/ (was tscn_s/). Rename the shell
scene.tscn -> levels/game_shell.tscn and every PascalCase scene to snake_case
(Player.tscn -> player.tscn, MainMenu.tscn -> main_menu.tscn, etc.) so the
case-insensitive web/macOS filesystems can't alias two files together.

Done as a scripted move: each file travels with its .uid; every quoted res:// path
across scenes, scripts, .tres, and project.godot's 9 autoloads is rewritten; the
.godot uid/class cache is rebuilt from scratch. Scenes still resolve by uid, so the
rewrite is belt-and-suspenders. Lint globs (run_tests.sh + both CI workflows) now
walk the new dirs; an orphan animation_tree.gd.uid and 7 pre-existing trailing-
whitespace lints (barrel/torch, never covered by the old root-only glob) are cleaned.

Full suite green on both sides. Asset consolidation (Assets/Animations/fonts ->
art/) is deferred — moving imported .glb/.png/.ttf is safer done in the editor.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_017KoYBYQgRyY1zDHXMsXY3V

tests/ui_layout_test.gd

@@ -145,7 +145,7 @@ func _find_touch(node: Node) -> Node:
 func _boot_shell(touch: bool) -> Node:
 	var dp: Node = root.get_node("/root/DP")
 	dp.call("set_value", "force_touch_controls", touch)
-	var scene: Node = load("res://scene.tscn").instantiate()
+	var scene: Node = load("res://levels/game_shell.tscn").instantiate()
 	root.add_child(scene)
 	current_scene = scene
 	await create_timer(0.8).timeout                          # let the shell build the level + HUD
@@ -203,7 +203,7 @@ func _run() -> void:
 	# Short viewport so the rebind list can't fit, then open options the way the button does, so we
 	# measure the real panel laid out — not a hidden one whose scrollbar hasn't been computed yet.
 	root.size = Vector2i(1024, 600)
-	var menu: Node = load("res://MainMenu.tscn").instantiate()
+	var menu: Node = load("res://ui/main_menu.tscn").instantiate()
 	root.add_child(menu)
 	await create_timer(0.3).timeout
 	if menu.has_method("_on_options_pressed"):