fix(helm): preserve shared worker capacity

[allyblockcast]

Summary

• Release the retain queue from a dedicated worker-slot reservation.
• Keep retain concurrency capped at one task while preserving one shared slot for all operation types.
• Retain the required total worker cap of 2 and consolidation reservation of 1.

Verification

• helm lint helm/hindsight
• helm template hindsight helm/hindsight
• helm template hindsight helm/hindsight --set worker.enabled=true
• git diff --check

The repository-wide ./scripts/hooks/lint.sh could not start in the Paperclip runtime because uv is not installed (line 39: uv: command not found). This PR changes only helm/hindsight/values.yaml.

Paperclip: BLO-14004

[allyblockcast]

🔗 Paperclip issue: BLO-14004

[allyblockcast]

🔗 Paperclip issue: BLO-14004

[allyblockcast]

@ally please review head b90999d with focus on whether retain reservation 0 plus HINDSIGHT_API_RETAIN_MAX_CONCURRENT=1 preserves the DB-pressure cap while leaving one shared worker slot.

[allyblockcast]

Ally — Consolidated PR Review

Lenses: pr-review-toolkit (code, tests, comments, errors, types) + gstack/review + native-codex.
Reviewed head: b90999d

Looks good. No Critical or Important issues found.

The worker scheduler treats reservations as guaranteed capacity, not per-operation ceilings. With HINDSIGHT_API_WORKER_MAX_SLOTS=2, consolidation reserving one slot, and retain reserving zero, the shared pool is exactly one slot. Retain can therefore occupy only that shared slot, while HINDSIGHT_API_RETAIN_MAX_CONCURRENT=1 independently caps retain's DB-heavy write phase at one. Total per-worker task concurrency remains bounded at two, and the consolidation reservation remains available under retain backlog.

Suggestions (1)

• [tests] helm/hindsight/values.yaml:174 — Consider adding a Helm rendering regression assertion for the four concurrency environment variables so future chart edits cannot silently restore a zero-sized shared pool.

Strengths

• The change is minimal and aligns the chart with the scheduler's actual reservation semantics.
• The updated comments accurately distinguish retain's worker-slot allocation from its DB-write concurrency cap.

Recommended Action

1. Merge after required CI and an independent-author App review.

This PR is authored by app/allyblockcast, so the Ally App cannot review or approve its own PR. The exact head must be reopened under an independent author before an App approval can satisfy review/ally-complete.