Update from upstream

The brand pack (workspace/brand/), licensed fonts (private-fonts/) and .env are Git-ignored, so an update never touches them. The team's own skills and instruction edits can conflict.

1. git status. Commit the person's local work first, or ask; never use a bare git stash.
2. Add the remote once: git remote add upstream https://github.com/langchain-ai/design-agent.git. Then git fetch upstream and read the new entries in CHANGELOG.md for breaking changes.
3. Merge upstream/main into the person's branch. In conflicts, keep their skills and instruction edits and take upstream's code; ask when a conflict touches both.
4. uv sync, uv run design-agent doctor, uv run pytest -q, uv run design-agent skills verify.
5. If sandbox/setup.sh changed: uv run design-agent sandbox build && uv run design-agent sandbox test; for Managed Deep Agents, also uv run design-agent sandbox publish (the snapshot name follows the recipe's hash).
6. Try the update on a test copy (uv run mda deploy --name design-agent-test), then deploy the team's agent after a yes (design-agent-deploy).