fix(ci): add cursor variant to docker-smoke-test.yml

Missing from PR #301 — opencode was added in #258 but cursor was not
included in the smoke test matrix.

Author: thepagent

.github/workflows/docker-smoke-test.yml

@@ -19,6 +19,7 @@ jobs:
           - { dockerfile: Dockerfile.gemini, suffix: "-gemini", agent: "gemini", agent_args: "--acp" }
           - { dockerfile: Dockerfile.copilot, suffix: "-copilot", agent: "copilot", agent_args: "--acp" }
           - { dockerfile: Dockerfile.opencode, suffix: "-opencode", agent: "opencode", agent_args: "acp" }
+          - { dockerfile: Dockerfile.cursor, suffix: "-cursor", agent: "cursor-agent", agent_args: "acp" }
     runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@v6