Render context compaction as standard work log entries

- Replace timeline marker treatment with normal grouped work rows
- Switch context window meter to an SVG ring and show auto-compaction

Author: juliusmarminge

apps/web/src/components/chat/MessagesTimeline.tsx

@@ -147,25 +147,11 @@ export const MessagesTimeline = memo(function MessagesTimeline({
       }
 
       if (timelineEntry.kind === "work") {
-        if (timelineEntry.entry.display === "timeline-marker") {
-          nextRows.push({
-            kind: "work",
-            id: timelineEntry.id,
-            createdAt: timelineEntry.createdAt,
-            groupedEntries: [timelineEntry.entry],
-          });
-          continue;
-        }
         const groupedEntries = [timelineEntry.entry];
         let cursor = index + 1;
         while (cursor < timelineEntries.length) {
           const nextEntry = timelineEntries[cursor];
-          if (
-            !nextEntry ||
-            nextEntry.kind !== "work" ||
-            nextEntry.entry.display === "timeline-marker"
-          )
-            break;
+          if (!nextEntry || nextEntry.kind !== "work") break;
           groupedEntries.push(nextEntry.entry);
           cursor += 1;
         }
@@ -328,21 +314,6 @@ export const MessagesTimeline = memo(function MessagesTimeline({
         (() => {
           const groupId = row.id;
           const groupedEntries = row.groupedEntries;
-          const markerEntry =
-            groupedEntries.length === 1 && groupedEntries[0]?.display === "timeline-marker"
-              ? groupedEntries[0]
-              : null;
-          if (markerEntry) {
-            return (
-              <div className="my-3 flex items-center gap-3">
-                <span className="h-px flex-1 bg-border" />
-                <span className="rounded-full border border-border bg-background px-2.5 py-1 text-[10px] uppercase tracking-[0.14em] text-muted-foreground/80">
-                  {markerEntry.label}
-                </span>
-                <span className="h-px flex-1 bg-border" />
-              </div>
-            );
-          }
           const isExpanded = expandedWorkGroups[groupId] ?? false;
           const hasOverflow = groupedEntries.length > MAX_VISIBLE_WORK_LOG_ENTRIES;
           const visibleEntries =

apps/web/src/session-logic.ts

@@ -40,7 +40,6 @@ export interface WorkLogEntry {
   command?: string;
   changedFiles?: ReadonlyArray<string>;
   tone: "thinking" | "tool" | "info" | "error";
-  display?: "timeline-marker";
   toolTitle?: string;
   itemType?: ToolLifecycleItemType;
   requestKind?: PendingApproval["requestKind"];
@@ -523,9 +522,6 @@ function toDerivedWorkLogEntry(activity: OrchestrationThreadActivity): DerivedWo
   if (requestKind) {
     entry.requestKind = requestKind;
   }
-  if (activity.kind === "context-compaction") {
-    entry.display = "timeline-marker";
-  }
   const collapseKey = deriveToolLifecycleCollapseKey(entry);
   if (collapseKey) {
     entry.collapseKey = collapseKey;