[Feature] Support buildStrategy: "local" for Docker stacks — build the image on the control-plane host and ship it to the target server

[ApocalypseYun]

Problem

Local build (buildStrategy: "local") works great for app stacks: clone + build on the Openship host, transfer the artifact to the target server. But for docker / docker-compose projects it's hardcoded to "server" (apps/api/src/modules/deployments/build-config.ts), so the full docker build load lands on the target machine.

My setup: the Openship control-plane server is strong (4C/8G), but the business target servers are small (2C/4G). Docker builds (especially npm install inside the image) put real pressure on the small boxes and have caused deploy-time resource exhaustion.

Proposal

Extend buildStrategy: "local" to docker stacks:

1. Build the image on the API host (docker build with the locally-cloned context)
2. Transfer it to the target daemon via docker save → stream → docker load
3. Deploy on the target as usual

The pieces largely exist already:

• packages/adapters/src/runtime/image-transfer.ts — streams one image between two daemons as pure data (used today for same-server migration handover), no registry needed
• packages/adapters/src/runtime/local-build.ts — shared local-build pipeline (clone → build → transfer callback)
• The deploy wizard already has the "This Machine / Server" build-location picker; it would just stop being hidden for docker stacks

Notes / open questions

• Compose stacks with multiple services: transfer each service's built image
• Architecture mismatch (e.g. arm64 Mac control plane → amd64 server) would need docker buildx --platform
• Could reuse handoverImages (one-time image handover used by migration) as the deploy-side seam

[Hydralerne]

fixed ?