fix: filter web timeline assistant marks

.yoi/tickets/00001KY1ZKCPC/item.md

@@ -2,7 +2,7 @@
 title: 'Backend runtime経由の操作をprotocol transportへ統一しTUI同等にする'
 state: 'planning'
 created_at: '2026-07-21T09:20:07Z'
-updated_at: '2026-07-22T06:36:51Z'
+updated_at: '2026-07-22T07:08:39Z'
 assignee: null
 readiness: 'draft'
 ---

.yoi/tickets/00001KY1ZKCPC/thread.md

@@ -376,3 +376,41 @@ Verification:
 - `git diff --check`
 
 ---
+
+<!-- event: comment author: assistant at: 2026-07-22T07:04:51Z -->
+
+## Comment
+
+Requested Web Console timeline-bar display change before implementation:
+
+- Keep user-message markers/items as they are today.
+- For assistant display in the timeline bar, show only the last assistant item within each turn.
+
+Implementation plan:
+- Locate the Web timeline-bar projection/rendering path.
+- Change only the timeline-bar item derivation/filtering, not the underlying transcript/event model.
+- Add/update focused Web tests if there is a projection helper; otherwise verify through existing Web check and keep the diff scoped.
+
+---
+
+<!-- event: implementation_report author: assistant at: 2026-07-22T07:08:39Z -->
+
+## Implementation report
+
+Implementation report for Web Console timeline-bar assistant filtering:
+
+- Added `selectConsoleTimelineLines()` in `web/workspace/src/lib/workspace/console/model.ts`.
+- The selector keeps every `user` line in the timeline selection.
+- Assistant lines are grouped by user-delimited turns, and only the last assistant line in each turn is selected.
+- Non-user/non-assistant lines remain excluded from the timeline bar selection.
+- Updated `+page.svelte` timeline layout construction to use the selector before converting selected lines to timeline marks. Positioning still uses the full transcript line count, so marks remain aligned to scroll position.
+- Added a focused model test for `user, assistant, tool, assistant, user, assistant, assistant` to assert the selected timeline items are `u1`, `a2`, `u2`, and `a4`.
+
+Verification:
+- `cd web/workspace && deno test --allow-read=src --allow-env=VSCODE_TEXTMATE_DEBUG src/lib/workspace/console/model.test.ts`
+- `cd web/workspace && deno task check` passed with 0 errors; it still reports the existing 2 a11y warnings in `+page.svelte`.
+- `git diff --check`
+
+Note: `deno fmt --check` on the touched files still reports existing formatting changes outside this patch scope, so it was not used as the gating check for this small change.
+
+---

web/workspace/src/lib/workspace/console/model.test.ts

@@ -3,7 +3,9 @@ import {
   createConsoleProjector,
   projectConsole,
   segmentsToText,
+  selectConsoleTimelineLines,
   workerConsoleHref,
+  type ConsoleLine,
 } from "./model.ts";
 
 declare const Deno: {
@@ -24,6 +26,16 @@ function assertEquals<T>(actual: T, expected: T): void {
   }
 }
 
+function consoleLine(id: string, kind: ConsoleLine["kind"]): ConsoleLine {
+  return {
+    id,
+    kind,
+    title: kind,
+    body: id,
+    source: "event",
+  };
+}
+
 Deno.test("workerConsoleHref encodes runtime and worker target authority", () => {
   assert(
     workerConsoleHref({
@@ -857,3 +869,20 @@ Deno.test("projectConsole reseeds visible rows from segment rotation", () => {
     ["user:after rotation seed"],
   );
 });
+
+Deno.test("selectConsoleTimelineLines keeps all users and only last assistant per turn", () => {
+  const items = [
+    consoleLine("u1", "user"),
+    consoleLine("a1", "assistant"),
+    consoleLine("tool1", "tool"),
+    consoleLine("a2", "assistant"),
+    consoleLine("u2", "user"),
+    consoleLine("a3", "assistant"),
+    consoleLine("a4", "assistant"),
+  ];
+
+  assertEquals(
+    selectConsoleTimelineLines(items).map(({ item, index }) => `${index}:${item.id}`),
+    ["0:u1", "3:a2", "4:u2", "6:a4"],
+  );
+});

web/workspace/src/lib/workspace/console/model.ts

@@ -64,6 +64,39 @@ export type ConsoleProjection = {
   lastEventId: string | null;
 };
 
+export type ConsoleTimelineLineSelection = {
+  item: ConsoleLine;
+  index: number;
+};
+
+export function selectConsoleTimelineLines(
+  items: ConsoleLine[],
+): ConsoleTimelineLineSelection[] {
+  const selected: ConsoleTimelineLineSelection[] = [];
+  let lastAssistant: ConsoleTimelineLineSelection | null = null;
+
+  const flushAssistant = () => {
+    if (lastAssistant) {
+      selected.push(lastAssistant);
+      lastAssistant = null;
+    }
+  };
+
+  items.forEach((item, index) => {
+    if (item.kind === "user") {
+      flushAssistant();
+      selected.push({ item, index });
+      return;
+    }
+    if (item.kind === "assistant") {
+      lastAssistant = { item, index };
+    }
+  });
+
+  flushAssistant();
+  return selected;
+}
+
 export type WorkerTarget = {
   runtime_id: string;
   worker_id: string;

web/workspace/src/routes/w/[workspaceId]/runtimes/[runtimeId]/workers/[workerId]/console/+page.svelte

@@ -17,6 +17,7 @@
     import { fitTextarea } from "$lib/workspace/console/textarea-fit";
     import {
         createConsoleProjector,
+        selectConsoleTimelineLines,
         type ConsoleEventInput,
         type ConsoleLine,
         type ConsoleProjection,
@@ -643,8 +644,10 @@
         metrics: ScrollMetrics,
     ): TimelineLayout {
         const denominator = Math.max(items.length - 1, 1);
-        const rawMarks = items
+        const rawMarks = selectConsoleTimelineLines(items)
-            .map((item, index) => timelineMarkForLine(item, index, denominator))
+            .map(({ item, index }) =>
+                timelineMarkForLine(item, index, denominator)
+            )
             .filter((mark): mark is TimelineMark => mark !== null);
         const trackHeight = timelineTrackHeight(metrics);
         const positioned = positionTimelineMarks(rawMarks, trackHeight);