[Frontend][A11y] Associate the post-revision Review lock reason with disabled decisions

[Chris0Jeky]

Context

PR #2448 renders a live status while the post-revision truth refresh disables the Review decision rail. Independent accessibility review found the status is attached through aria-describedby to the non-focusable ReviewMain wrapper, while the four disabled decision controls only receive the older editLock description linkage. Refs #1964, #2215, and PR #2448.

Current impact

The live role=status announcement and focus restoration work, so the reviewer is not silently trapped. However, assistive technology inspecting the disabled Reject, Request edit, Defer, or Approve control does not get a direct relationship to the refresh-lock explanation.

Acceptance

• Give ReviewDecisionRail an explicit refresh-lock reason or description id contract that reaches every disabled decision control.
• Preserve the existing editing and saving lock descriptions and cancel behavior.
• Avoid dangling aria-describedby references when no explanation is rendered.
• Prove the association in an attached-DOM component test for all rendered decision controls and retain the browser focus-return proof.

[Chris0Jeky]

[Claude lane claim v2]
lane: alpha-product-trust (session taskdeck-alpha-85, Taskdeck-Alpha checkout)
issue: #2461
base: 61e94f6
residual acceptance: ReviewDecisionRail exposes an explicit refresh-lock reason/description id contract that reaches every disabled decision control (Reject, Request edit, Defer, Approve); existing editing and saving lock descriptions and cancel behavior preserved; no dangling aria-describedby when no explanation is rendered; attached-DOM component test proves the association for all rendered controls and the browser focus-return proof is retained
owned paths/modules: frontend/taskdeck-web/src/views/paper/review/ReviewDecisionRail.vue; frontend/taskdeck-web/src/views/paper/review/ReviewMain.vue; frontend/taskdeck-web/src/tests/views/paper/review/ReviewDecisionRail.spec.ts; frontend/taskdeck-web/src/tests/views/paper/review/ReviewMain.spec.ts; locale catalogs only if a new string is required
shared-path leases: PaperReviewView.vue, PaperReviewView.spec.ts, useProposalDisplayNames.ts and ReviewProposalCard.vue stay leased to PR #2541 (a9); this slice does not touch them
parallel-safe work: worktree codex-2305 (Inbox poll family) is disjoint
open PRs/branches/review threads checked: PR #2448 merged (post-revision truth barrier, origin of #2460/#2461), PR #2456 merged, PR #2516 merged 13:00Z (origin of #2524), PR #2528 merged (retry unavailable evidence), PR #2541 open and held by a9 (touches PaperReviewView.vue and ReviewProposalCard.vue, not these files); #2460, #2461 and #2524 are serialized in this one worktree, in the order #2524, #2461, #2460
human or decision gates: none
status: active