Telemetry sink should restart its flush timer when configuration changes

[Mosas2000]

Problem
telemetry-sink.js keeps the original interval when configureSink() updates flushIntervalMs.

Why it matters
Changing sink settings does not take effect until the process restarts or the sink is reset manually.

Acceptance criteria

• Recreate the flush timer when timing settings change
• Keep queue behavior consistent across reconfiguration
• Add a test for updating flushIntervalMs at runtime