Add CORS debug logging and endpoint

backend/app/main.py

@@ -20,6 +20,7 @@ async def lifespan(app: FastAPI):
     # Startup
     logger.info("Starting Patherly API server...")
     logger.info(f"Environment: {'Development' if settings.DEBUG else 'Production'}")
+    logger.info(f"ALLOW_RAILWAY_ORIGINS: {settings.ALLOW_RAILWAY_ORIGINS}")
     # Note: In production, use Alembic migrations instead of init_db
     # await init_db()
     yield
@@ -87,3 +88,13 @@ async def root():
 async def health_check():
     """Health check endpoint."""
     return {"status": "healthy"}
+
+
+@app.get("/debug/cors")
+async def debug_cors():
+    """Debug endpoint to check CORS configuration."""
+    return {
+        "allow_railway_origins": settings.ALLOW_RAILWAY_ORIGINS,
+        "cors_mode": "regex" if settings.ALLOW_RAILWAY_ORIGINS else "list",
+        "allowed_origins": settings.allowed_origins if not settings.ALLOW_RAILWAY_ORIGINS else "*.up.railway.app (regex)"
+    }