Deacon heartbeat stamping can stop updating the beacon label after recovery from a stuck kill

Summary

The Deacon's beacon bead can stop receiving fresh heartbeat: label updates after recovery from a stuck-kill event. Manual heartbeat commands do not re-stamp the label once it is wedged.

Observed behavior

• The beacon label stops advancing.
• Restarting related processes with a clean environment does not restore label updates.
• Explicit heartbeat commands also fail to refresh the beacon label.

Impact

• Beacon state becomes stale and no longer reflects Deacon liveness.
• Operators lose confidence in the heartbeat indicator.
• This weakens monitoring and post-incident diagnostics even when other automation continues to run.

Evidence

Observed after a stuck-kill recovery window on 2026-06-05, where the heartbeat label remained frozen while unrelated environment fixes had no effect.

Expected behavior

The heartbeat cycle should either resume stamping automatically after recovery or surface a clear failure when beacon updates are no longer possible.

Suggested fix

Inspect the heartbeat-stamping path for:

• state not being reinitialized after stuck-kill recovery
• stale label update guards that never clear
• failures that are swallowed instead of surfacing an actionable error

A watchdog for "heartbeat label has not advanced within N intervals" would also make this class of failure easier to detect.