Expand transactional editing evidence and compare authority cases

Assistant: codex
Assistant-Model: gpt-6-astra
Assistant-Session: 01a0cffe-206f-7323-89d3-b20ca4cf4bf9

research/candidates/VersionCheckedMutation.md

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+---
+title: Version-Checked Mutation
+status: draft
+maturity: hypothesis
+families: [mutation, authority]
+scales: [L2, L6]
+admission: research-candidate-only
+---
+
+# Version-Checked Mutation
+
+Context: a proposal depends on a previously observed record. Problem: concurrent
+updates can invalidate that base. Consistency competes with throughput and user effort.
+
+Proposed solution: send an expected version with the proposal; the authority checks
+it atomically with validation and commit. A mismatch rejects the attempt. Preserve
+the draft, fetch current state and reconsider intent before a new attempt. An
+operation identity for safe retries is separate from the version precondition.
+
+Consequences: lost updates can be detected, but high contention creates repeated
+review. Unconditional or commutative operations may need different preconditions;
+blindly retrying with a new version can overwrite another user's intent.
+
+Evidence: T01 documents Kubernetes conditional PUT; T02 documents a different GitLab
+failure surface and optional last_commit_id, insufficient to prove identical atomic
+semantics. One precise mechanism use, not two verified frontend uses. Recurrence of
+this frontend configuration: unknown. Hypothesis only.
+
+Proposed connection: rejection creates work for [Local Draft State](LocalDraftState.md)
+and [Mutation Outcome Tracking](MutationOutcomeTracking.md).
+
+T01–T05 refer to [TransactionalEvidenceExpansion](../reviews/TransactionalEvidenceExpansion.md).
+Connections are research proposals, not admitted graph edges.
+Reasoning exercise: [VC-01](../walkthroughs/VC01-TransactionalAdministration.md).