fix: Makefile supports docker compose v2 plugin and v1 standalone

DC variable auto-detects available command at build time.
Also fixes backup and dev targets that incorrectly used $(DC).yml.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

Makefile

@@ -3,6 +3,9 @@
 
 .PHONY: help start stop restart status logs clean setup init-peers build build-api build-webui
 
+# Detect docker compose command (v2 plugin preferred, fallback to v1 standalone)
+DC := $(shell docker compose version >/dev/null 2>&1 && echo "docker compose" || echo "docker-compose")
+
 # Default target
 help:
 	@echo "Personal Internet Cell - Management Commands"
@@ -51,52 +54,52 @@ init-peers:
 # Management commands
 start:
 	@echo "Starting Personal Internet Cell..."
-	docker-compose up -d
+	$(DC) up -d
 	@echo "Services started. Check status with 'make status'"
 
 stop:
 	@echo "Stopping Personal Internet Cell..."
-	docker-compose down
+	$(DC) down
 	@echo "Services stopped."
 
 restart:
 	@echo "Restarting Personal Internet Cell..."
-	docker-compose restart
+	$(DC) restart
 	@echo "Services restarted."
 
 status:
 	@echo "Personal Internet Cell Status:"
 	@echo "================================"
-	docker-compose ps
+	$(DC) ps
 	@echo ""
 	@echo "API Status:"
 	@curl -s http://localhost:3000/health || echo "API not responding"
 
 logs:
 	@echo "Showing logs from all services..."
-	docker-compose logs -f
+	$(DC) logs -f
 
 # Individual service commands
 start-dns:
 	@echo "Starting DNS service..."
-	docker-compose up -d dns
+	$(DC) up -d dns
 
 start-api:
 	@echo "Starting API service..."
-	docker-compose up -d api
+	$(DC) up -d api
 
 start-wg:
 	@echo "Starting WireGuard service..."
-	docker-compose up -d wireguard
+	$(DC) up -d wireguard
 
 start-webui:
 	@echo "Starting WebUi service..."
-	docker-compose up -d webui
+	$(DC) up -d webui
 
 # Maintenance commands
 clean:
 	@echo "Cleaning up containers and volumes..."
-	docker-compose down -v
+	$(DC) down -v
 	docker system prune -f
 	@echo "Cleanup complete."
 
@@ -116,21 +119,21 @@ restore:
 # Development commands
 dev:
 	@echo "Starting development environment..."
-	docker-compose -f docker-compose.yml -f docker-compose.dev.yml up -d
+	$(DC) -f docker-compose.yml -f docker-compose.dev.yml up -d
 
 build:
 	@echo "Building API service..."
-	docker-compose build api
+	$(DC) build api
 
 build-api:
 	@echo "Rebuilding API (no cache)..."
-	docker-compose build --no-cache api
-	docker-compose up -d api
+	$(DC) build --no-cache api
+	$(DC) up -d api
 
 build-webui:
 	@echo "Rebuilding Web UI (no cache)..."
-	docker-compose build --no-cache webui
-	docker-compose up -d webui
+	$(DC) build --no-cache webui
+	$(DC) up -d webui
 
 # Testing commands
 test: