Add exact owner-approved work acceptance - #503

Summary

Add an owner-only /typechat accept <artifact-id>:<acceptance-sha256> command to record agreed work on an Issue or Discussion, separately from publishing an advisory response or authorizing a coding agent.

1. /typechat draft prepares the conversational response and, only when ready, a separate work-acceptance preview.
2. The owner reviews the proposed goal, scope, non-goals, testable criteria, policy, and contribution references.
3. The exact acceptance command posts one top-level Accepted work record.

Proposals require in_scope, ready_for_owner_decision, no open questions, and complete nonempty terms and criteria. Other readiness states cannot produce an acceptance preview. These checks support, rather than replace, the owner's judgment.

Authorization and safeguards

• Response publication and acceptance have different hashes, markers, and intent names. /typechat publish cannot accept work, and /typechat reply artifacts cannot authorize acceptance.
• Preserve owner/default-branch authorization, successful producer provenance, scan binding, context/policy/PR freshness, expiry, and durable intent-before-write checks.
• Repeated acceptance of the same exact proposal is a no-op; uncertain writes block retries, and edited or removed records are not automatically rewritten or recreated.
• Reuse the target-scoped manual publisher. It runs no model and has no repository-content write permission. Acceptance does not launch or authorize an automated implementation run, increase a budget, assign work, close anything, or approve merging.
• Commands remain command-only. Optional inline implementation guidance is deferred to Automation: support implementation notes with work acceptance #502, not implemented here.

The sealed bundle and publication intent advance to v3. Context and scan bindings remain v1; the direct-reply command marker remains v2 to preserve stable command identity. Old artifacts must be regenerated rather than converted to bypass freshness checks.

Integration and validation

This branch is based on the merged #499 safety fix. The sole-native-noop completion guard is preserved before sealing, including rejection of missing, incomplete, unknown, and mixed failure outputs on both response and acceptance paths.

• 191 offline automation tests pass with Node 24.22.1, including actual authored-script execution for Issue/Discussion × draft/reply/accept.
• Both workflows compile with pinned gh-aw v0.93.5 in strict mode: zero warnings and no generated-file drift on repeat compilation.
• 95 local documentation links/anchors and whitespace checks pass.
• Project-direction policy, dependencies, runtime pin, shared model/budget settings, action pins, and backlog workflow are unchanged.

Rollout

Update the operator and contributor guidance, and record the previously verified Issue reply and duplicate-free rerun from run 41226698016. Those live results do not verify the new acceptance extension, manual publication, or Discussions.

No live acceptance has been triggered. After human review and merge, test acceptance only on genuinely agreed, in-scope work using a fresh draft, review the exact preview, and verify one record plus a no-op retry. Verify Issue and Discussion writers separately. This PR does not accept or implement the feature requested in #75, and it does not enable the future implementation budget.