diff --git a/packages/app/e2e/sidebar/sidebar-leading-slot.spec.ts b/packages/app/e2e/sidebar/sidebar-leading-slot.spec.ts
new file mode 100644
index 000000000..2c513bc41
--- /dev/null
+++ b/packages/app/e2e/sidebar/sidebar-leading-slot.spec.ts
@@ -0,0 +1,55 @@
+import { expect, test } from "../fixtures"
+import { openSidebar, withSession } from "../actions"
+import { pawworkSidebarSelector } from "../selectors"
+
+test("pawwork sidebar merges pin into the status slot with a stable title baseline", async ({
+  page,
+  sdk,
+  gotoSession,
+}) => {
+  const stamp = Date.now()
+  await withSession(sdk, `i150 regression ${stamp}`, async (session) => {
+    await gotoSession(session.id)
+    await openSidebar(page)
+
+    const sidebar = page.locator(pawworkSidebarSelector).first()
+    const row = sidebar.locator(`[data-session-id="${session.id}"]`).first()
+    const title = row.locator("span", { hasText: `i150 regression ${stamp}` }).first()
+
+    const leftOf = async (locator: typeof title) => {
+      const rect = await locator.evaluate((el) => el.getBoundingClientRect())
+      return Math.round(rect.left)
+    }
+
+    // Baseline: unpinned, no hover.
+    await page.mouse.move(0, 0)
+    await expect(row).toBeVisible()
+    const baseline = await leftOf(title)
+
+    // Hover must not shift the title horizontally (action slot grows on the right).
+    await row.hover()
+    expect(await leftOf(title)).toBe(baseline)
+
+    // Pin via row menu; the row rerenders in the pinned section.
+    await row.locator('[data-action="session-row-menu"]').click()
+    await page.getByRole("menuitem", { name: /pin session/i }).click()
+    const pinnedRow = sidebar
+      .locator(`[data-component="pawwork-sidebar-pinned"] [data-session-id="${session.id}"]`)
+      .first()
+    await expect(pinnedRow).toBeVisible()
+
+    const pinnedTitle = pinnedRow.locator("span", { hasText: `i150 regression ${stamp}` }).first()
+    await page.mouse.move(0, 0)
+    expect(await leftOf(pinnedTitle)).toBe(baseline)
+    await pinnedRow.hover()
+    expect(await leftOf(pinnedTitle)).toBe(baseline)
+
+    // Pin button should occupy the row's leading slot, not a separate column.
+    const pinButton = pinnedRow.locator('[data-action="pawwork-session-pin"][data-pinned="true"]').first()
+    await expect(pinButton).toBeVisible()
+    const pinRect = await pinButton.evaluate((el) => el.getBoundingClientRect())
+    const rowRect = await pinnedRow.evaluate((el) => el.getBoundingClientRect())
+    expect(Math.round(pinRect.left - rowRect.left)).toBe(8)
+    expect(Math.round(pinRect.width)).toBe(24)
+  })
+})
diff --git a/packages/app/src/pages/layout/sidebar-items.tsx b/packages/app/src/pages/layout/sidebar-items.tsx
index bfe33e453..e9fc147ad 100644
--- a/packages/app/src/pages/layout/sidebar-items.tsx
+++ b/packages/app/src/pages/layout/sidebar-items.tsx
@@ -96,6 +96,7 @@ const SessionRow = (props: {
   warmPress: () => void
   warmFocus: () => void
   titleContent?: JSX.Element
+  leadingSlot?: JSX.Element
 }): JSX.Element => {
   const title = () => sessionTitle(props.session.title)
   const indicator = () => {
@@ -103,7 +104,7 @@ const SessionRow = (props: {
     if (props.hasPermissions()) return <div class="size-1.5 rounded-full bg-surface-warning-strong" />
     if (props.hasError()) return <div class="size-1.5 rounded-full bg-text-diff-delete-base" />
     if (props.unseenCount() > 0) return <div class="size-1.5 rounded-full bg-text-interactive-base" />
-    return null
+    return props.leadingSlot ?? null
   }
 
   return (
@@ -195,6 +196,7 @@ export const SessionItem = (props: SessionItemProps): JSX.Element => {
       warmPress={() => warm(2, "high")}
       warmFocus={() => warm(2, "high")}
       titleContent={props.titleContent?.({ session: props.session, title: () => sessionTitle(props.session.title) ?? "" })}
+      leadingSlot={!props.level && props.leadingSlot ? props.leadingSlot(props.session) : undefined}
     />
   )
 
@@ -206,9 +208,6 @@ export const SessionItem = (props: SessionItemProps): JSX.Element => {
         style={{ "padding-left": `${8 + (props.level ?? 0) * 16}px` }}
       >
         <div class="flex min-w-0 items-center gap-1">
-          <Show when={props.leadingSlot && !props.level}>
-            <div class="shrink-0">{props.leadingSlot?.(props.session)}</div>
-          </Show>
           <div class="min-w-0 flex-1">
             <Show
               when={!tooltip()}