fix: resolve EADDRINUSE and Traefik routing issues

Remove host port binding from docker-compose to avoid port conflicts
and add dokploy-network for proper Traefik discovery. Add graceful
error handling for EADDRINUSE in HTTP server.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

docker-compose.yml

@@ -1,17 +1,21 @@
 services:
   solidtime-mcp:
     build: .
-    ports:
-      - "${PORT:-3045}:3045"
     environment:
       - PORT=3045
       # Optional: default SolidTime API URL for all sessions.
       # Clients can override this via the x-solidtime-api-url header.
       - SOLIDTIME_API_URL=${SOLIDTIME_API_URL:-https://app.solidtime.io}
     restart: unless-stopped
+    networks:
+      - dokploy-network
     healthcheck:
       test: ["CMD", "wget", "--no-verbose", "--tries=1", "--spider", "http://localhost:3045/health"]
       interval: 30s
       timeout: 5s
       retries: 3
       start_period: 10s
+
+networks:
+  dokploy-network:
+    external: true