Story-2141: Vega proposal panel — collapsed presentation

Founder decision (2026-07-08): Vega/Mira frame-edit proposals render collapsed, not enthroned on each field. The crown variant is rejected — availability-over-visibility. The Brief reads clean; a single quiet strip carries the pending proposals, and the Inbox rail (frame_ratify, Epic-2123) owns the nagging. This story delivers that collapsed presentation and wires Confirm/Reject through the existing ratify rail — no new accept surface.

What landed

• VegaProposalStrip (src/components/matter-detail/brief/vega-proposal-strip.tsx) — collapsed by default: one strip with Vega's avatar and a pluralized count ("2 proposals from Vega"). Click expands a diff-style panel of the pending proposals. Renders null when nothing is pending, so the Brief layout is untouched unless Vega has something waiting.
• Confirm/Reject through the existing rail — each row's buttons call the matter's useAppAcceptMatterFrameProposal / useAppRejectMatterFrameProposal mutations (keyed by frame field), the same accept/reject the inline field rail already uses. No second ratify surface. The field with a mutation in flight shows the PrimaryButton spinner.
• Motion doctrine — expand/collapse rides the shared MICRO_TRANSITION inside an AnimatePresence (height + opacity), symmetric enter/exit; the chevron rotates on the same token. Lazy m.* components only.
• Multi-proposal stacking — every proposed field folds into the one strip; the count and the expanded list both scale.
• Deep-link seam — the Brief page reads ?proposal=<field> (useSearchParams) and passes it as focusField; the strip opens expanded and scrolls that row into view, highlighted. This is the landing an Inbox frame_ratify item links to (producer lands later, Epic-2123).
• Data helper — pendingProposals(brief) in presentation.ts lists proposed fields + their values; pendingConfirmationCount now derives from it (one source).
• i18n — Mira.proposals (count/region/tag/ confirm/confirming/reject) added to en + hi; count uses an ICU plural. Field labels reuse the existing MatterDetail.brief keys.

Storybook (verify here)

• MatterDetail/VegaProposalStrip → Collapsed — the resting strip, one proposal.
• MatterDetail/VegaProposalStrip → Expanded — full proposed value + Confirm/Reject.
• MatterDetail/VegaProposalStrip → Multi — several proposals stacked.
• MatterDetail/VegaProposalStrip → Diff — the strikethrough before → after.
• MatterDetail/VegaProposalStrip → DeepLink — opens expanded, targeted row highlighted.
• MatterDetail/VegaProposalStrip → Empty — nothing renders (Brief stays clean).
• MatterDetail/VegaProposalStrip → Playground — Confirm spins, then the row clears.

Verification

• pnpm lint — clean (one pre-existing <img> warning in add-matter, untouched).
• pnpm test — 165 files / 1026 tests green (added pendingProposals cases).
• pnpm build — green.

Live-data seams: (1) proposals derive from the frame resolution "proposed" markers; the true before/after diff needs the frame-versions read endpoint, so live rows show the proposed value and the strikethrough previous is an optional prop the producer fills when that lands. (2) The deep-link consumer is built here; the Inbox frame_ratify producer that emits ?proposal=<field> lands with Epic-2123. Confirm/Reject against real proposed fields is the on-staging check (AC 2).