Add fotos.carloselugo.com photo-upload service

Event photo upload app with OAuth2 (Google Drive), Caddy route, and
env-var-driven compose config. Refresh token persists to token.json
so re-auth isn't needed after container restarts.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

photo-upload/Dockerfile

@@ -0,0 +1,15 @@
+FROM node:18-alpine
+
+WORKDIR /app
+
+COPY package*.json ./
+RUN npm install --omit=dev
+
+COPY . .
+
+# tmp_uploads se crea en runtime, pero lo dejamos listo por si acaso
+RUN mkdir -p tmp_uploads
+
+EXPOSE 3000
+
+CMD ["node", "server.js"]