Add Phase 1 MVP: D&D text-adventure server

FastAPI + Postgres backend with fastapi-users auth, games/characters
CRUD, and a WebSocket chat endpoint where an x.ai Grok DM narrates
play, rolls dice, and maintains character sheets via tool calls.
React + Tailwind frontend covers registration/login, game list and
creation, participation-code join flow, character viewer, and a
real-time chat session view. Docker Compose skeleton (Postgres +
backend) included; Caddy/frontend container wiring is deferred to
the deploy milestone.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

frontend/src/api/characters.ts

@@ -0,0 +1,18 @@
+import { apiFetch } from "./client";
+
+export interface Character {
+  id: string;
+  owner_id: string;
+  name: string;
+  race: string | null;
+  char_class: string | null;
+  level: number;
+  stats: Record<string, number>;
+  description: string;
+  created_at: string;
+  updated_at: string;
+}
+
+export const listCharacters = () => apiFetch<Character[]>("/api/characters");
+
+export const getCharacter = (id: string) => apiFetch<Character>(`/api/characters/${id}`);