fix: project-prefix networks and volumes to prevent cross-project isolation breach

[Jaro-c]

Problem

Networks and volumes without an explicit name: use the bare compose key (e.g. default, db-data). Two projects with the same key share the same network/volume, breaking isolation and risking data corruption.

Root cause

• engine/network.rs create_networks: uses bare name when no config.name set
• engine/volume.rs create_volumes: same issue for volumes
• resolve_network_name / resolve_network_mode: returns bare key, not prefixed name

Fix

When no explicit name: is set, use {project}_{key}. External networks/volumes are unaffected.