Summary

• Rework pprof startup to bind before launching the server, surface listener errors, and shut the server down on exit.
• Validate tracer providers up front and add a defensive no-op tracer fallback for unexpected service names.
• Make zero-rate waits context-aware while preserving realtime stats merging before finalization.
• Stabilize the metric time-offset end-to-end test with deterministic manual collection.
• Harden the dgg2motel corpus test script cleanup and per-run exit-code handling.

Impact

This removes lifecycle and stability edge cases in trace generation, realtime shutdown, metric testing, and corpus replay tooling. Failures that previously could panic or surface late now return clearer errors.

Validation

• make test
• make lint
• make build