feat(integration): consume Baton v1.1 task graph features in Retort commands

[JustAGhosT]

Summary

Baton v1.1 platform features are now available enough to stop treating labels, subtasks, comments, and relations as opaque JSON in Retort. Update Retort commands to use Baton first-class graph primitives.

Scope

• /sync-backlog: read/write labels, hierarchy, and blocking relations.
• /import-issues: map GitHub labels to Baton labels instead of only storing them in context JSON.
• /document-history: post related task activity/comments and link history docs.
• /plan: optionally create parent tasks and subtasks.
• /orchestrate: honor Baton blocked_by and related task graph ordering.
• /team-*: pick up/comment on Baton-owned or preferred-agent tasks.
• Add Retort label conventions, likely via .agentkit/spec/labels.yaml plus rendered reference docs.

Acceptance criteria

• Commands can round-trip Baton labels without duplicate label creation.
• GitHub-imported labels are visible/queryable in Baton.
• Orchestration refuses blocked tasks based on Baton relations.
• Plan output can create or update a Baton parent/subtask tree.
• Tests cover idempotent label/task sync and relation-aware dispatch.

Source

Created during Baton/GitHub consolidation on 2026-07-07 from Baton task 2e2b9388-2422-4161-b0d5-8ffca2d3b7ee.