feat: Raspberry Pi deployment — Dockerfile, CI/CD workflows, actuator

Backend:
- backend/Dockerfile: multi-stage build (local + ci-image targets)
  - eclipse-temurin:21-jre-alpine runtime, non-root user caloriecounter
  - DOCKER_BUILDKIT=0 + native JAR build pattern for ARM64 Pi runner
- pom.xml: add spring-boot-starter-actuator
- application.yml: expose /actuator/health (liveness probe for Docker healthcheck)

CI/CD:
- .gitea/workflows/ci.yml: Maven test on pi-runner (push + PR)
- .gitea/workflows/docker.yml: build + push calorie-counter-api:latest/:sha
  - Triggers after CI passes (workflow_run) to avoid OOM on single-capacity Pi
  - Docker login before Maven build (avoids daemon timeout after heavy CPU)
  - Deploys immediately via docker.sock to /home/andris/homelab/calorie-counter/

Mobile:
- api.ts: update baseURL default to https://calories.amlab.dev
  (LAN fallback: http://10.18.1.135:8085 via WireGuard)

Homelab changes pushed directly via Gitea MCP:
- homelab/calorie-counter/docker-compose.yml (port 8085, 120s start_period)
- homelab/calorie-counter/.env.example
- homelab/.gitea/workflows/deploy-calorie-counter.yml (cron every 10 min)
- homelab/backup/backup.sh (added calorie-counter pg_dump)

mobile/src/services/api.ts

@@ -2,7 +2,10 @@
 import axios from 'axios';
 import AsyncStorage from '@react-native-async-storage/async-storage';
 
-const BASE_URL = process.env.API_BASE_URL ?? 'http://localhost:8080';
+// Production: https://calories.amlab.dev  (Nginx Proxy Manager → Pi:8085)
+// Local dev:  http://10.18.1.135:8085     (Pi LAN, via WireGuard if off-network)
+// Override:   set API_BASE_URL env var in your .env file
+const BASE_URL = process.env.API_BASE_URL ?? 'https://calories.amlab.dev';
 
 const api = axios.create({
   baseURL: BASE_URL,