shared page: expandable receipt details on split transactions

The item list existed only on the owner's transactions page — the person
a meal or order was split WITH could see the amount but never what was in
it. getSharedTransactions now carries the same order_platform LATERAL the
transactions page uses, and rows with a receipt get the same disclosure
arrow + OrderDetails expansion. The shared viewer is a split participant,
so canAccessTransactions already authorises the order API for them; meal
rows keep the verdict UI (the partner records their own), bridge rows
stay review-free.

src/lib/queries.ts

@@ -866,6 +866,11 @@ export async function getSharedTransactions(ownerId: number, tagIds?: number[],
       COALESCE(t.owner_id, s.owner_id) as owner_id,
       p_owner.name as owner_name,
       COALESCE(src.created_at, t.created_at) as created_at,
+      -- Receipt flag, same LATERAL the transactions page uses: the shared
+      -- viewer is a split participant, so the order API authorises them —
+      -- without the flag here the disclosure arrow (and the item list behind
+      -- it) existed only on the owner's page.
+      order_ctx.platform as order_platform,
       json_agg(json_build_object(
         'split_id', ts.id,
         'participant_id', ts.participant_id,
@@ -879,6 +884,12 @@ export async function getSharedTransactions(ownerId: number, tagIds?: number[],
     LEFT JOIN transaction_overrides o ON o.transaction_id = t.id
     LEFT JOIN statements s ON s.id = t.statement_id
     LEFT JOIN participants p_owner ON p_owner.id = COALESCE(t.owner_id, s.owner_id)
+    LEFT JOIN LATERAL (
+      SELECT em.platform
+        FROM expense_metadata em
+       WHERE em.transaction_id = t.id OR em.matched_transaction_id = t.id
+       LIMIT 1
+    ) order_ctx ON true
     LEFT JOIN transactions src ON src.reconciled_with_id = t.id AND src.statement_id IS NULL
     WHERE (
         (
@@ -892,7 +903,7 @@ export async function getSharedTransactions(ownerId: number, tagIds?: number[],
       AND ${EXCLUDE_RECONCILED_SOURCE}
     ${tagClause}
     ${participantClause}
-    GROUP BY t.id, o.category_override, o.merchant_normalized, o.notes, s.bank_name, s.currency, s.owner_id, p_owner.name, src.created_at
+    GROUP BY t.id, o.category_override, o.merchant_normalized, o.notes, s.bank_name, s.currency, s.owner_id, p_owner.name, src.created_at, order_ctx.platform
     ORDER BY t.transaction_date DESC
   `, params);