Fix/recall and live cleanup

[lutefd]

Why

Agents had no direct, low-ceremony way to answer questions such as “what are my live Fabric notes?” This led to stale checkpoints, unrelated thread pointers, guessed commands, and excessive session setup.

This adds direct note recall, explicit thread controls, and safe cleanup for ephemeral Fabric state.

Protocol impact

• Adds fabric list with durability, status, issue, PR, area, and path filters.
• Adds fabric clean live and fabric clean runtime, previewing by default and requiring --apply.
• Adds fabric thread list, use, and clear.
• Separates actionable direction from resolved challenge history.
• Adds the focused fabric-recall skill.
• Adds machine capabilities for record listing and thread management.
• No schema changes.

Verification

• go test ./...
• Verified resolved challenges remain queryable but do not inflate actionable counts.
• Verified live cleanup preserves candidate and durable records.
• Verified runtime cleanup cannot delete direction events.
• Verified thread selection and clearing.
• Removed initial dogfood artifacts.
• Final local state: 0 live, 5 candidate, 7 durable records.

Direction changes

• Removed the simulated PR 1 review-ingest dogfood direction.
• No reusable project direction was added or modified.

Checklist

• I kept unrelated changes out of this PR.
• I updated protocol docs, schemas, and fixtures when required. No update was required.
• I preserved immutable event and provider-neutral behavior.