Switch Docker base from Alpine to Slim for arm64 onnxruntime compatibility

Alpine uses musl libc but onnxruntime-node on arm64 requires glibc
(ld-linux-aarch64.so.1). node:24-slim (Debian) includes glibc natively.

Author: prih

Dockerfile

@@ -1,4 +1,4 @@
-FROM node:24-alpine AS build
+FROM node:24-slim AS build
 
 WORKDIR /app
 
@@ -19,7 +19,7 @@ COPY ui/ ./ui/
 RUN npm run build
 
 # --- Runtime ---
-FROM node:24-alpine
+FROM node:24-slim
 
 WORKDIR /app