fix: add CORS middleware to server for Tauri webview requests

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

server/app.py

@@ -1,4 +1,5 @@
 from fastapi import FastAPI, WebSocket
+from fastapi.middleware.cors import CORSMiddleware
 
 from core.db import ProcessedDB
 from .config import DB_PATH
@@ -7,6 +8,13 @@ from . import ws
 
 app = FastAPI(title="8-cut Server")
 
+app.add_middleware(
+    CORSMiddleware,
+    allow_origins=["*"],
+    allow_methods=["*"],
+    allow_headers=["*"],
+)
+
 db = ProcessedDB(DB_PATH)
 
 app.include_router(files.router, prefix="/api")