feat(client): Version helper + sync-version script; project.godot config/version

- Add scripts/sync-version to sync root /VERSION into client/project.godot
- Add Version GDScript helper (reads application/config/version)
- Test coverage: 2 tests for Version.string() and footer()
- Synced config/version="0.01-alpha" to project.godot

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

scripts/sync-version

@@ -0,0 +1,13 @@
+#!/usr/bin/env bash
+# Sync the single source of truth (/VERSION) into the Godot client's project.godot
+# (application/config/version). Run after bumping /VERSION.
+set -euo pipefail
+root="$(cd "$(dirname "$0")/.." && pwd)"
+version="$(tr -d '[:space:]' < "$root/VERSION")"
+proj="$root/client/project.godot"
+if grep -q '^config/version=' "$proj"; then
+  sed -i "s|^config/version=.*|config/version=\"$version\"|" "$proj"
+else
+  sed -i "s|^\(config/name=.*\)|\1\nconfig/version=\"$version\"|" "$proj"
+fi
+echo "synced client config/version = \"$version\""