fix(docker): build on node:24-slim to match lockfile's npm 11

The committed package-lock.json was generated by npm 11 (Node 24). On
node:20-slim (npm 10) npm ci reported webpack/terser/ajv "missing from
lock file" because npm 10 resolves Next.js's bundled webpack tree
differently. Match the build toolchain to the lockfile generator.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

Author: guillermoscript

Dockerfile

@@ -1,4 +1,4 @@
-FROM node:20-slim AS base
+FROM node:24-slim AS base
 
 # Install dependencies
 FROM base AS deps