feat: Phase 4.5 — Déploiement multi-plateforme v0.4.5

- service.v: --install-service / --uninstall-service / --service-status
  Windows (sc.exe SCM), Linux systemd, Linux openrc — auto-détection OS
- main.v: nouveaux flags service, help mis à jour
- Dockerfile: multi-stage (V from source → alpine:3.20 minimal)
- docker-compose.yml: prêt à l'emploi avec healthcheck
- scripts/install.sh: one-liner Linux (detect OS/arch, build, install)
- scripts/install.ps1: one-liner Windows PowerShell

Docs: ROADMAP Phase 4.5 marqué DONE, version 0.4.5

docker-compose.yml

@@ -0,0 +1,21 @@
+services:
+  ntfy-bridge:
+    build: .
+    image: ntfy-bridge:latest
+    container_name: ntfy-bridge
+    restart: unless-stopped
+    ports:
+      - "127.0.0.1:9090:9090"
+    volumes:
+      - ./ntfy-bridge.yaml:/etc/ntfy-bridge/ntfy-bridge.yaml:ro
+      - ./dashboard.html:/etc/ntfy-bridge/dashboard.html:ro
+    environment:
+      - TZ=America/Toronto
+      - NTFY_TOKEN=${NTFY_TOKEN:-}
+      - NTFY_HMAC_SECRET=${NTFY_HMAC_SECRET:-}
+    healthcheck:
+      test: ["CMD", "wget", "--no-verbose", "--tries=1", "--spider", "http://localhost:9090/health"]
+      interval: 30s
+      timeout: 5s
+      retries: 3
+      start_period: 10s