fix(build): rename threadSummary.ts — case-collision broke the Windows release

threadSummary.ts (pure helpers) and ThreadSummary.tsx (chip component) lived in
the same directory differing only by case. On the case-insensitive Windows
release runner, RoomTimeline's extensionless import of ./thread/ThreadSummary
resolved .ts BEFORE .tsx and matched the helper module → rolldown
MISSING_EXPORT "ThreadSummary" — invisible on every Linux/macOS build (and the
cause of the earlier masked pdf.worker failure). Helper module renamed to
threadSummaryData.ts (+ test), 3 importers updated.

Prevention: new caseCollision.test.ts walks src/ and fails on any same-directory
names differing only by case (extensionless compare, so Foo.tsx vs foo.ts is
caught) — verified it fails on the pre-rename tree. Runs in the hard CI gate.

Gates: tsc clean, eslint/prettier clean, build OK, 658/659 tests (1 IDB skip).

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

src/app/features/room/thread/threadSummaryData.test.ts

@@ -0,0 +1,133 @@
+import { test } from 'node:test';
+import assert from 'node:assert/strict';
+import { EventStatus, MatrixEvent, RelationType } from 'matrix-js-sdk';
+import { getThreadSummary, isPendingThreadReply } from './threadSummaryData';
+
+// getThreadSummary reads either the live Thread (preferred) or the
+// server-aggregated `m.thread` bundle. We stub only the members it touches and
+// cast through `unknown` to MatrixEvent, mirroring the light mocking used in
+// the state tests.
+
+type ThreadStub = { length: number; lastReplyTs?: number };
+type BundleStub = { count: number; latestTs?: number };
+
+const makeRootEvent = (opts: { thread?: ThreadStub; bundle?: BundleStub }): MatrixEvent => {
+  const thread = opts.thread
+    ? {
+        length: opts.thread.length,
+        lastReply: () =>
+          opts.thread?.lastReplyTs === undefined
+            ? null
+            : ({ getTs: () => opts.thread?.lastReplyTs } as unknown as MatrixEvent),
+      }
+    : undefined;
+
+  return {
+    getThread: () => thread,
+    getServerAggregatedRelation: (relType: string) => {
+      if (relType !== RelationType.Thread || !opts.bundle) return undefined;
+      return {
+        count: opts.bundle.count,
+        latest_event:
+          opts.bundle.latestTs === undefined
+            ? undefined
+            : { origin_server_ts: opts.bundle.latestTs },
+      };
+    },
+  } as unknown as MatrixEvent;
+};
+
+// ---------------------------------------------------------------------------
+// getThreadSummary
+// ---------------------------------------------------------------------------
+
+test('prefers the live thread: count from length, latestTs from lastReply', () => {
+  const rootEvent = makeRootEvent({
+    thread: { length: 3, lastReplyTs: 1700 },
+    bundle: { count: 99, latestTs: 1 },
+  });
+  assert.deepEqual(getThreadSummary(rootEvent), { count: 3, latestTs: 1700 });
+});
+
+test('live thread with no replies yields undefined latestTs', () => {
+  const rootEvent = makeRootEvent({ thread: { length: 0 } });
+  assert.deepEqual(getThreadSummary(rootEvent), { count: 0, latestTs: undefined });
+});
+
+test('falls back to the server bundle when no live thread', () => {
+  const rootEvent = makeRootEvent({ bundle: { count: 5, latestTs: 1234 } });
+  assert.deepEqual(getThreadSummary(rootEvent), { count: 5, latestTs: 1234 });
+});
+
+test('bundle without latest_event yields undefined latestTs', () => {
+  const rootEvent = makeRootEvent({ bundle: { count: 2 } });
+  assert.deepEqual(getThreadSummary(rootEvent), { count: 2, latestTs: undefined });
+});
+
+test('returns undefined when there is neither a thread nor a bundle', () => {
+  const rootEvent = makeRootEvent({});
+  assert.equal(getThreadSummary(rootEvent), undefined);
+});
+
+// ---------------------------------------------------------------------------
+// isPendingThreadReply
+// ---------------------------------------------------------------------------
+
+const ROOT = '$root:server';
+
+const makeReply = (opts: {
+  status: EventStatus | null;
+  threadRootId?: string;
+  relation?: { rel_type?: string; event_id?: string } | null;
+}): MatrixEvent =>
+  ({
+    status: opts.status,
+    threadRootId: opts.threadRootId,
+    getRelation: () => opts.relation ?? null,
+  }) as unknown as MatrixEvent;
+
+test('SENDING with matching threadRootId is pending', () => {
+  const event = makeReply({ status: EventStatus.SENDING, threadRootId: ROOT });
+  assert.equal(isPendingThreadReply(event, ROOT), true);
+});
+
+test('NOT_SENT with matching threadRootId is pending', () => {
+  const event = makeReply({ status: EventStatus.NOT_SENT, threadRootId: ROOT });
+  assert.equal(isPendingThreadReply(event, ROOT), true);
+});
+
+test('SENDING resolved via the m.thread relation content is pending', () => {
+  const event = makeReply({
+    status: EventStatus.SENDING,
+    relation: { rel_type: RelationType.Thread, event_id: ROOT },
+  });
+  assert.equal(isPendingThreadReply(event, ROOT), true);
+});
+
+test('SENT (confirmed) event is not pending', () => {
+  const event = makeReply({ status: EventStatus.SENT, threadRootId: ROOT });
+  assert.equal(isPendingThreadReply(event, ROOT), false);
+});
+
+test('null status is not pending', () => {
+  const event = makeReply({ status: null, threadRootId: ROOT });
+  assert.equal(isPendingThreadReply(event, ROOT), false);
+});
+
+test('SENDING but for a different thread is not pending', () => {
+  const event = makeReply({ status: EventStatus.SENDING, threadRootId: '$other:server' });
+  assert.equal(isPendingThreadReply(event, ROOT), false);
+});
+
+test('SENDING with a non-thread relation is not pending', () => {
+  const event = makeReply({
+    status: EventStatus.SENDING,
+    relation: { rel_type: RelationType.Reference, event_id: ROOT },
+  });
+  assert.equal(isPendingThreadReply(event, ROOT), false);
+});
+
+test('SENDING with no relation and no threadRootId is not pending', () => {
+  const event = makeReply({ status: EventStatus.SENDING });
+  assert.equal(isPendingThreadReply(event, ROOT), false);
+});