chore: retire orphaned PR640 SLO benchmark Colima datadisk #1180

Decision

Retire the orphaned Colima datadisk left by the closed PR #640 performance experiment after preserving the provenance and confirming the current product state.

Provenance

• PR: feat(dashboard): quantify cases and preserve project journeys #640 — feat(dashboard): quantify cases and preserve project journeys
• PR state: CLOSED, not merged (mergedAt=null, mergeCommit=null)
• Experiment profile: lineageweave-slo
• Datadisk: /Users/seonghobae/.colima/_lima/_disks/colima-lineageweave-slo/datadisk
• Logical size: 100 GiB
• Host allocated size before retirement: approximately 28.30 GiB
• ext4 UUID: b390d983-073a-4860-91f1-52e7d3bcbbb7
• Creation provenance: PR640 performance/concurrency investigation; k6 posts latency and vCPU/cold-warm sweeps; an approximately 18 GiB PostgreSQL benchmark clone was recorded.
• The Colima profile was already deleted; the orphan datadisk remained.

Current-state finding

PR640 itself was not merged, but its dashboard functionality has successor implementations in current main and later merged work. The PR640 20 ms performance result was not adopted as a protected-main product SLO; current documentation treats it as diagnostic evidence, not a production SLO or capacity ceiling.

The remaining datadisk is an old, unattached benchmark environment. The user explicitly authorized its deletion after this issue record. Current default Colima operations use a separate datadisk and named volumes.

Safety boundary

• Do not stop or restart the default Colima VM.
• Do not remove default Colima containers, images, volumes, or source worktrees.
• Delete only the exact orphan datadisk and its empty stale profile/store metadata if verified safe.
• Preserve the private investigation receipts and provenance reports under /Users/seonghobae/orca/reports/disk-cleanup-1791968290993204000/.

Evidence

• /Users/seonghobae/orca/reports/disk-cleanup-1791968290993204000/orphan-disk-preserved.json
• /Users/seonghobae/orca/reports/disk-cleanup-1791968290993204000/pr640-disk-necessity-final.json
• /Users/seonghobae/orca/reports/disk-cleanup-1791968290993204000/pr640-timeline.json
• /Users/seonghobae/orca/reports/disk-cleanup-1791968290993204000/pr640-view.json
• /Users/seonghobae/orca/reports/lineageweave-ssd-import-20261012/capacity-proposal.md

Deletion will be verified by exact path absence, post-delete host capacity measurement, and unchanged default Colima container census.