feat(groups): add traceable relay handoff notes and explicit step instructions #617

Problem

Relay tasks currently receive preceding answers as generic historical data. The next employee does not receive a structured, inspectable record of its place in the relay, its explicitly assigned work, source turns, and the material actually included. The same predecessor can also be included through both group history and the supplemental handoff path.

Scope and readiness

The requester reviewed the local “RoleWeave 任务交接说明与协作者上下文方案” and explicitly requested implementation, an Issue, a PR, and review by Hu. This issue tracks phase one: relay handoff notes. It is a subset of task-level collaborator context; delegation, review workflows, live parallel coordination, and cross-task memory remain follow-up work.

Acceptance criteria

• Allow optional, explicit per-step instructions for a relay; do not infer responsibilities or acceptance from job titles.
• Before each relay step, assemble a bounded snapshot containing the original task excerpt, current recipient/step and instructions, next recipient when present, and completed predecessor excerpts with source identities/timestamps.
• Persist the same handoff snapshot that entered model input and show it in a collapsible client view, including missing instructions, truncation/redaction and omitted-source notices.
• Deduplicate predecessor turns against ordinary group history; preserve the existing context/input budgets and prioritize the immediate predecessor.
• Preserve failed/interrupted predecessor blocking and group/workspace isolation. Completed output must not be presented as accepted/approved work.
• Keep personal tasks, parallel groups and historical records without the new optional data compatible.

Components and dependencies

Shared group/turn contracts, group request/store validation, thread-context assembly, group renderer and localization. Reuse existing relay sequencing, trusted completion records and turn storage. No extra model summarization call, new external service or permission transfer.

Validation

Deterministic context tests (source deduplication, budgets, sanitization and exact persisted-input matching); group API/storage tests (instructions, invalid input, relay sequence, failure and isolation); renderer tests (composer instructions and persisted handoff display); TypeScript builds and repository checks; browser QA for expanded/collapsed handoff notes. Record unavailable platform checks and CI status in the PR.

Risks and rollback

Optional durable fields require current readers; retain workspace backups when reverting to older strict readers. Summaries remain bounded excerpts with explicit source references. Revert the implementation without editing historical records to fabricate compatibility.