Unify service check result formatting

[codeforester]

Summary

• Replace the parallel check_service()/health_label() dispatch with one CheckResult path carrying probe status, display label, and check detail.
• Preserve current status/check output for the catalog check types.
• Add regression coverage for missing HTTP targets so status and check cannot drift again.

Validation

• bats tests/services_test.bats
• BASE_DEMO_SERVICES_STATE_DIR=$(mktemp -d "${TMPDIR:-/tmp}/base-demo-status.XXXXXX") ./bin/base-demo-services status && BASE_DEMO_SERVICES_STATE_DIR=$(mktemp -d "${TMPDIR:-/tmp}/base-demo-check.XXXXXX") ./bin/base-demo-services check
• ./tests/validate.sh
• env GRADLE_USER_HOME=/private/tmp/base-demo-gradle-89 bats tests/demo_test.bats tests/services_test.bats tests/environments_test.bats tests/infra_test.bats tests/go_api_test.bats tests/python_api_test.bats tests/java_services_test.bats tests/native_services_test.bats tests/demo_console_test.bats
• git diff --check

Note: the full BATS run used a fresh Gradle user home with escalated local execution because sandboxed Gradle initialization hit a local socket restriction.

Fixes #90