Replace TS game shell with Bevy/Rust client, add auth service, purge legacy archive

- Replace apps/game (TypeScript/Vite/R3F) with a Bevy 0.16 Rust client
  featuring main menu, star map, and flight states
- Add services/auth: Express + better-auth server with SpacetimeDB
  token exchange endpoint
- Delete archive/legacy-static/ (old JS demos, CSS, assets)
- Update docs pages (architecture, gameplay, roadmap, social, overview)
  to reflect Bevy pivot
- Clean up workspace config: remove apps/game from pnpm workspace,
  update dev scripts, tsconfig, and AGENTS.md files
- Add .vscode/settings.json for Rust tooling

apps/docs/src/data/nav.ts

@@ -21,7 +21,7 @@ export const navSections: NavSection[] = [
       { path: "/docs/gameplay", icon: "◉", label: "Gameplay Loop" },
       { path: "/docs/ships", icon: "◇", label: "Ships & Fitting" },
       { path: "/docs/economy", icon: "⇄", label: "Economy & Industry" },
-      { path: "/docs/social", icon: "✧", label: "Progression & Social" },
+      { path: "/docs/social", icon: "✧", label: "Progression & World" },
       { path: "/docs/ship-ai", icon: "◈", label: "Ship AI - Zora" },
       { path: "/docs/roadmap", icon: "⊞", label: "Roadmap" },
       { path: "/docs/todo", icon: "⊡", label: "Implementation Status" },