Initial commit: AI Dungeon clone (FastAPI backend + React frontend)

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01KFsGHju9szibJJa2YJcdbg

backend/app/main.py

@@ -0,0 +1,55 @@
+from pathlib import Path
+
+from fastapi import FastAPI
+from fastapi.middleware.cors import CORSMiddleware
+from fastapi.staticfiles import StaticFiles
+from starlette.exceptions import HTTPException as StarletteHTTPException
+
+from .database import engine
+from .migrations import bootstrap
+from .routers import adventures, debug, scenarios, scripts, settings, story_cards
+
+bootstrap(engine)
+
+app = FastAPI(title="AI D&D")
+
+app.add_middleware(
+    CORSMiddleware,
+    allow_origins=["http://localhost:5173", "http://127.0.0.1:5173"],
+    allow_methods=["*"],
+    allow_headers=["*"],
+)
+
+app.include_router(scenarios.router)
+app.include_router(adventures.router)
+app.include_router(story_cards.router)
+app.include_router(scripts.router)
+app.include_router(settings.router)
+app.include_router(debug.router)
+
+
+@app.get("/api/health")
+def health():
+    return {"ok": True}
+
+
+# In production, serve the built frontend (frontend/dist) as static files.
+class SPAStaticFiles(StaticFiles):
+    """Serve index.html for unknown paths so client-side routes (/play/3)
+    survive a page reload. API routes are matched before this mount."""
+
+    async def get_response(self, path, scope):
+        try:
+            response = await super().get_response(path, scope)
+        except StarletteHTTPException as exc:
+            if exc.status_code != 404:
+                raise
+            return await super().get_response("index.html", scope)
+        if response.status_code == 404:
+            return await super().get_response("index.html", scope)
+        return response
+
+
+frontend_dist = Path(__file__).resolve().parent.parent.parent / "frontend" / "dist"
+if frontend_dist.is_dir():
+    app.mount("/", SPAStaticFiles(directory=frontend_dist, html=True), name="frontend")