Opencode V2 sbx agent

Makefile

@@ -0,0 +1,38 @@
+# Utilities for running the OpenCode agent in a Docker Sandbox.
+# Requires the `sbx` CLI: https://docs.docker.com/ai/sandboxes/install/
+#
+# `sbx` doesn't have a nested sandbox-in-sandbox mode, so these targets are
+# meant to be run on your host machine from this directory (where sbxenv.yaml
+# lives), not from inside another sandbox.
+
+NAME             ?= opencode-v2
+AGENT            ?= opencode
+IMAGE_TAG        ?= opencode-v2:local
+OPENCODE_VERSION ?= 2.0.26
+
+.PHONY: help cli-check image build install
+
+help:
+	@echo "NAME=$(NAME) AGENT=$(AGENT) OPENCODE_VERSION=$(OPENCODE_VERSION)"
+	@echo ""
+	@echo "  make image                        build the $(IMAGE_TAG) image pinning the opencode CLI version"
+	@echo "  make build   [OPENCODE_VERSION=...] build the image and register it with sbx as a local template"
+	@echo "  make install                      install the opencode-sandbox shim to ~/.local/bin"
+
+cli-check:
+	@command -v sbx >/dev/null 2>&1 || { \
+		echo "sbx CLI not found. Install it: https://docs.docker.com/ai/sandboxes/install/"; \
+		exit 1; \
+	}
+	@sbx version
+
+image:
+	docker build --build-arg OPENCODE_VERSION=$(OPENCODE_VERSION) -t $(IMAGE_TAG) .
+
+build: cli-check image
+	docker image save $(IMAGE_TAG) -o /tmp/opencode-v2.tar
+	sbx template load /tmp/opencode-v2.tar
+
+install:
+	sh ./install.sh
+