fix(chat): keep rectification sessions findable and keep the delivery card

Rectification answers now advance chat_sessions.updated_at (BUG-704).
A ?c= id missing from the loaded page is fetched before anyone may call
it deleted (BUG-705). The range card no longer has a post-card tie-break
button; live questions leave the card visible with adopt locked
(BUG-706/708). Spoken copy bans 相对支持度 (BUG-709).

Task docs assigned 700-704; qizheng already took 700-703.

frontend/src/components/rectification-range-delivery.tsx

@@ -21,19 +21,19 @@ export function RectificationRangeDelivery({
   acceptingCandidateId,
   readonly,
   onAccept,
-  onTieBreak,
+  adoptLocked,
 }: Readonly<{
   result: RectificationCandidateResult;
   acceptingCandidateId: string | null;
   readonly: boolean;
   onAccept: (candidateId: string) => void;
-  onTieBreak?: () => void;
+  adoptLocked?: boolean;
 }>) {
   const delivery: RangeDeliveryProjection | null = result.rangeDelivery;
   const range = delivery?.range ?? result.credibleRange;
   const eventCount = delivery?.event_count ?? 0;
   const selected = result.selectedTime;
-  const busy = Boolean(acceptingCandidateId) || readonly;
+  const busy = Boolean(acceptingCandidateId) || readonly || adoptLocked;
   const columns = delivery?.columns ?? [];
   const title = range
     ? eventCount > 0
@@ -68,15 +68,10 @@ export function RectificationRangeDelivery({
       {delivery?.provenance_line ? (
         <p className="rectification-range-delivery__provenance">{delivery.provenance_line}</p>
       ) : null}
-      {delivery?.tie_break_available && onTieBreak && !readonly ? (
-        <button
-          type="button"
-          className="rectification-range-delivery__tie-break"
-          disabled={busy}
-          onClick={onTieBreak}
-        >
-          {RECTIFICATION_USER_COPY.rangeDeliveryTieBreakEntry}
-        </button>
+      {adoptLocked ? (
+        <p className="rectification-range-delivery__narrow">
+          {RECTIFICATION_USER_COPY.rangeDeliveryAdoptLocked}
+        </p>
       ) : null}
       {delivery?.tie_break_note ? (
         <p className="rectification-range-delivery__narrow">{delivery.tie_break_note}</p>