ProcessSupervisor child-stderr relay double-stamps log level + adds task-label noise — trim to [ProcessSupervisor] [childSource] message

Friction (operator-flagged 2026-06-27)

Orchestrator logs are brittle / too long. ProcessSupervisorService.writeChildStderr re-logs each child stderr line by prepending [ProcessSupervisor] ${task.label} stderr: to the raw child line — which already carries its own [LEVEL] [source] prefix. Result: the level is double-stamped and the <task-label> stderr: framing is noise.

[…] [INFO] [ProcessSupervisor] memory miniSummary backfill stderr: [INFO] [MemoryService] miniSummary backfill complete: 9/9 …

should be:

[…] [INFO] [ProcessSupervisor] [MemoryService] miniSummary backfill complete: 9/9 …

Fix

In writeChildStderr (ai/daemons/orchestrator/services/ProcessSupervisorService.mjs), strip the child's leading [LEVEL] from the re-logged message (the outer level already carries it via getChildLogLevel(line)) + drop ${task.label} stderr::

const level = this.getChildLogLevel(line);
this.writeLog?.(level, `[ProcessSupervisor] ${line.replace(/^\[(LOG|INFO|WARN|ERROR)\]\s*/, '')}`);

Acceptance Criteria

• Child stderr lines log as [ProcessSupervisor] [<childSource>] <message> — single level stamp (the child's, preserved), no <task-label> stderr: framing.
• Level is lossless: a child [WARN]/[ERROR] line still logs at WARN/ERROR (the outer level already = getChildLogLevel).
• A child line with no recognized [LEVEL] prefix passes through unstripped at the ERROR default (existing getChildLogLevel behavior).
• ProcessSupervisorService spec updated for the trimmed format + a WARN/ERROR-preservation case.

Avoided trap

• NOT dropping the level entirely — the surviving stamp is the CHILD's parsed level (verified: line 345 already uses getChildLogLevel), so WARN/ERROR are never masked as INFO.
• Per-line supervised-task attribution is dropped (the task.label); recoverable from the framed Starting <task> + serial heavy-maintenance + the child source. Decision, not accident.

Authored by Vega (@neo-opus-vega · Claude Opus 4.8); friction→gold from an operator log-readability flag. Filed via gh relay (gh-author neo-opus-ada = shared-token artifact).