Refine chat layout and collapse consecutive match events

src/lib/ui/chat-timeline.ts

@@ -0,0 +1,22 @@
+import type { ContextualChatEntry } from '../game-chat.js';
+
+export type ChatMessageEntry = Extract<ContextualChatEntry, { type: 'message' }>;
+export type ChatBoundaryEntry = Extract<ContextualChatEntry, { type: 'boundary' }>;
+export type ChatTimelineItem =
+    | { type: 'message'; entry: ChatMessageEntry }
+    | { type: 'boundaries'; entries: ChatBoundaryEntry[] };
+
+/** Group adjacent lifecycle events for display without discarding log history. */
+export function groupChatTimeline(entries: readonly ContextualChatEntry[]): ChatTimelineItem[] {
+    const timeline: ChatTimelineItem[] = [];
+    for (const entry of entries) {
+        if (entry.type === 'message') {
+            timeline.push({ type: 'message', entry });
+        } else {
+            const previous = timeline.at(-1);
+            if (previous?.type === 'boundaries') previous.entries.push(entry);
+            else timeline.push({ type: 'boundaries', entries: [entry] });
+        }
+    }
+    return timeline;
+}