Add grid agent milestone acceptance gate (#135)

.gitea/workflows/ci.yml

@@ -174,6 +174,9 @@ jobs:
               rm -f -- "$fingerprint_list"
             fi
             cargo run --locked -p metacrate-ci-matrix -- required-gate --evidence artifacts/ci/required-gate.json
+            test ! -e artifacts/ci/grid-agent-acceptance.jsonl
+            cargo test --locked -p metacrate-grid-agent --test acceptance_gate --all-features
+            METACRATE_SOURCE_COMMIT="${{ github.sha }}" cargo run --locked -p metacrate-grid-agent -- --acceptance-evidence artifacts/ci/grid-agent-acceptance.jsonl
             touch "$CARGO_TARGET_DIR/.metacrate-ready"
           ) 9>"$cache_lock"