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

ui/game_version.gd

@@ -0,0 +1,33 @@
+class_name GameVersion
+extends RefCounted
+## Single source of truth for the game's version string.
+##
+## The numeric version lives in project.godot (application/config/version) so it
+## also feeds export metadata; here we read it back and layer on the pre-release
+## CHANNEL and a human-readable STAGE label. We're pre-1.0 — every 0.x build is
+## understood to be unstable, in-development software (see the recommendations in
+## the commit / PR notes for why 0.x is the convention for early game dev).
+
+## Pre-release channel appended to the number, SemVer-style (e.g. 0.1.0-alpha).
+const CHANNEL: String = "alpha"
+
+## Friendly stage banner shown to players so it's unmistakably an early build.
+const STAGE: String = "Early Development Build"
+
+
+## Bare numeric version, e.g. "0.1.0". Read from project settings.
+static func number() -> String:
+	return str(ProjectSettings.get_setting("application/config/version", "0.0.0"))
+
+
+## Full version tag, e.g. "v0.1.0-alpha".
+static func string() -> String:
+	var s := "v" + number()
+	if not CHANNEL.is_empty():
+		s += "-" + CHANNEL
+	return s
+
+
+## Version tag + stage banner, e.g. "v0.1.0-alpha · Early Development Build".
+static func full() -> String:
+	return "%s · %s" % [string(), STAGE]