Improve Long-Running Task Orchestration

[nathanwhitbot]

Summary

Preserve durable loop iteration summaries in the task context ledger so later iterations receive compact continuity from prior loop turns. Durable loop task actions now render as durable_loop_iteration ledger entries with their iteration number, status, worker id, and summary, while failures, cancellations, waits, and explicitly high-value text still receive high priority.

This helps large, long-running objectives maintain working memory across bounded loop iterations without requiring every worker to use special summary keywords.

Validation

• go test ./internal/orchestrator
• go test ./...

[nathanwhit]

Reviewed the durable-loop iteration ledger entry change. The task.action handler now retains loop iteration summaries with iteration and worker context while still bounding routine entries through the existing ledger scoring path. CI is green.