acceptance: add daemon_vs_standalone test

[rolbk]

Summary

This PR adds acceptance tests comparing daemon and standalone operation modes.

This is part 4 of a series splitting #4853 into smaller, reviewable PRs. The original PR will be closed.

Main Changes

• Add daemon_vs_standalone test: Created acceptance/daemon_vs_standalone/test.py that runs end-to-end integration tests with both daemon and standalone modes.

• Extend integration tooling: Updated tools/end2end_integration/main.go to support standalone mode testing.

• Add integration helpers: Extended tools/integration/binary.go and tools/integration/integrationlib/common.go with helpers for standalone testing.

Testing

The tests are integrated in CI/CD as AT: daemon_vs_standalone_daemon and AT: daemon_vs_standalone_standalone.

Run locally with:

bazel test --test_output=streamed //acceptance/daemon_vs_standalone:test_ping
bazel test --test_output=streamed //acceptance/daemon_vs_standalone:test_standalone