Fix CORS_ORIGINS env parsing crash (pydantic-settings NoDecode), bump 0.1.1

list[str] settings fed from env were JSON-decoded by pydantic-settings
before the field validator ran, so a plain string like
CORS_ORIGINS=http://host:5009 raised JSONDecodeError on startup.
Annotate list env fields with NoDecode and parse CSV/JSON in the validator.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

backend/main.py

@@ -31,7 +31,7 @@ async def lifespan(app: FastAPI):
     yield
 
 
-app = FastAPI(title="StackPilot", version="0.1.0", lifespan=lifespan)
+app = FastAPI(title="StackPilot", version="0.1.1", lifespan=lifespan)
 
 app.add_middleware(
     CORSMiddleware,