Initialize uv-managed FastAPI backend

src/backend_server/main.py

@@ -0,0 +1,29 @@
+import os
+from typing import Literal
+
+from fastapi import FastAPI
+from fastapi.middleware.cors import CORSMiddleware
+from pydantic import BaseModel
+
+app = FastAPI(title="Entroia Backend", version="0.1.0")
+app.add_middleware(
+    CORSMiddleware,
+    allow_origins=[
+        origin.strip()
+        for origin in os.getenv(
+            "CORS_ORIGINS", "http://localhost:3000,http://localhost:5173"
+        ).split(",")
+        if origin.strip()
+    ],
+    allow_methods=["GET"],
+    allow_headers=["*"],
+)
+
+
+class HealthResponse(BaseModel):
+    status: Literal["ok"] = "ok"
+
+
+@app.get("/health", response_model=HealthResponse)
+def health() -> HealthResponse:
+    return HealthResponse()