generic_log_worker: share Worker runtime utilities

[lukevalenta]

Summary

• centralize Worker Sentry initialization
• share hex serialization for Durable Object hash state
• preserve existing persisted JSON formats

Stack

• depends on worker_build_config: share Worker config staging #285

Testing

• cargo fmt --all --check
• affected-crate tests and checks
• pedantic clippy with warnings denied
• cargo shear