fix(search): an edited message shows once, with its latest text (#288)

Server search also returns the m.replace events, so one message edited
twice came back as three rows. Fold edits into their message: one row
at the best-ranked position, showing the latest m.new_content and
pointing at the original event so Open jumps to the real message.

Fixes #288

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_017PCb59uY3UKqDqt7B6hzd5

src/app/features/message-search/useMessageSearch.test.ts

@@ -1,6 +1,7 @@
 import { test } from 'node:test';
 import assert from 'node:assert/strict';
 import {
+  foldEdits,
   filterGroupsByDateRange,
   filterGroupsByMsgType,
   filterGroupsByPinned,
@@ -109,3 +110,47 @@ test('filterGroupsByPinned: keeps pinned items and drops empty groups', () => {
     ['$2'],
   );
 });
+
+const sr = (eventId: string, ts: number, content: Record<string, unknown>) =>
+  ({
+    rank: 1,
+    result: {
+      event_id: eventId,
+      room_id: '!r:x',
+      origin_server_ts: ts,
+      type: 'm.room.message',
+      content,
+    },
+  }) as unknown as Parameters<typeof foldEdits>[0][number];
+
+test('foldEdits: one row per message, showing the latest edit (#288)', () => {
+  const edit = (id: string, ts: number, body: string) =>
+    sr(id, ts, {
+      body: `* ${body}`,
+      'm.new_content': { body },
+      'm.relates_to': { rel_type: 'm.replace', event_id: '$orig' },
+    });
+  const out = foldEdits([
+    edit('$e2', 30, 'Tuesday 11am room B'),
+    sr('$orig', 10, { body: 'Monday 10am room A' }),
+    edit('$e1', 20, 'Tuesday 10am room A'),
+    sr('$other', 5, { body: 'meeting notes' }),
+  ]);
+  assert.deepEqual(
+    out.map((r) => r.result.event_id),
+    ['$orig', '$other'],
+  );
+  assert.deepEqual(out[0].result.content['m.new_content'], { body: 'Tuesday 11am room B' });
+  assert.equal(out[0].result.content.body, 'Monday 10am room A');
+});
+
+test('foldEdits: an edit whose original did not match stands in for it', () => {
+  const out = foldEdits([
+    sr('$e1', 20, {
+      'm.new_content': { body: 'x' },
+      'm.relates_to': { rel_type: 'm.replace', event_id: '$orig' },
+    }),
+  ]);
+  assert.equal(out.length, 1);
+  assert.equal(out[0].result.event_id, '$orig');
+});