improvement(chat): restore stable inline tool activity headers and action summaries

Mothership v1.0.0 reintroduced the "Searching -> Searched -> Searching"
flicker that staging had fixed: between two calls of an open main-agent
activity, the header dropped to the past tense, lost its shimmer, and the
turn-level Thinking row appeared until the next call started. It also removed
the header icon and summarized headers as "<latest title> + N".

Stable in-progress header
- An open main-agent activity group (the streaming turn's tail, with nothing
  after its last call) stays in progress through gaps: present-tense label of
  its latest call, shimmer while that call runs or has succeeded. Only that
  tail group is open; a pending approval or terminal handoff later in the
  lane no longer re-opens earlier finished groups.
- Exactly one live indicator at a time: a main-agent search label now
  shimmers while its call streams or runs, and hides Thinking like any
  executing call. Once a trailing search finishes it shows static results, so
  the gap after it belongs to Thinking. The open-run check follows the same
  search/non-search split the transcript renders.
- assistantMessageHasVisibleActivity again lets that open group own the wait,
  so Thinking no longer appears between its calls. Thinking still shows at turn
  start, after prose closes the group, and after a failed or stopped call.
- Succeeded calls arrive with past-tense titles, so the open header maps them
  back through the exact inverse of the completed-verb rewrite
  (getToolActiveTitle). Subagent lanes use the same mapping; their open/active
  rules are unchanged.

Header icons
- Group headers and single inline rows render the running or latest call's
  icon again; a finished multi-call header shows the first successful call's
  icon, matching the summary's first phrase.

Summaries without "+N"
- Running headers show only the active call. Finished groups use the model's
  completedTitle when every call succeeded, and otherwise a fallback naming up
  to three distinct successful actions ("Navigated, read pages, clicked
  elements"), picked by first occurrence in transcript order. Failed calls are
  left out, and the " · N stopped/skipped" outcome suffix stays.
- A rebuilt action catalog covers the current tool surface: every visible
  catalog tool and operation, plus sim_cli commands. Each command's verb comes
  from its own display title, and the object comes from its resource path, so
  commands on one resource share a word ("Listed, read tables"). `mkdir`
  commands read as creating folders and `tables upsert` as writing table rows.
  Tools outside the catalog use their own completed title.

Separate finished activity groups
- groupByActivity still splits main-agent calls by activity id, but no longer
  merges finished groups into one header, so the completedGroupCount plumbing
  is removed, along with the unused getAgentIcon fallback parameter.

Author: waleedlatif1

apps/sim/app/workspace/[workspaceId]/home/components/message-content/components/agent-group/activity-stream.test.tsx

@@ -146,7 +146,7 @@ describe.each(['mothership', 'workflow', 'browser', 'deploy'])('%s activity', (a
       advance(100)
       render([tool('first', 'success'), tool('second')])
       render([tool('first', 'success'), tool('second', status)])
-      const label = agentName === 'mothership' ? 'Read first' : 'Reading first'
+      const label = 'Reading first'
       expect(header()?.textContent).toBe(label)
       advance(1500)
       expect(header()?.textContent).toBe(label)
@@ -164,7 +164,7 @@ describe.each(['mothership', 'workflow', 'browser', 'deploy'])('%s activity', (a
     advance(100)
     render([tool('first', 'success'), tool('second')])
     render([tool('first', 'success'), tool('second', 'success')], false)
-    const completed = 'Read second + 1'
+    const completed = 'Read files'
     expect(header()?.textContent).toBe(completed)
     expect(container.querySelector('[class*="shimmer"]')).toBeNull()
     advance(2000)
@@ -241,7 +241,7 @@ describe.each(['mothership', 'workflow', 'browser', 'deploy'])('%s activity', (a
     }
   )
 
-  it('shows the latest concrete action and keeps the complete history available', () => {
+  it('names the first distinct actions without a count and keeps the complete history', () => {
     render(
       [
         tool('first', 'success'),
@@ -251,7 +251,7 @@ describe.each(['mothership', 'workflow', 'browser', 'deploy'])('%s activity', (a
       ],
       false
     )
-    expect(header()?.textContent).toBe('Read fourth + 3')
+    expect(header()?.textContent).toBe('Read files, searched files, ran commands')
     const trigger = container.querySelector<HTMLElement>('[role="button"]')!
     act(() => trigger.click())
     expect(container.querySelector('[data-state="open"]')?.textContent).toBe(
@@ -281,26 +281,21 @@ describe.each(['mothership', 'workflow', 'browser', 'deploy'])('%s activity', (a
       expect(rows[0].querySelector('[class*="shimmer"]')).toBeNull()
     }
     const liveRow = rows[rows.length - 1]
-    expect(liveRow.textContent).toBe(agentName === 'mothership' ? 'Read second' : 'Reading second')
-    if (agentName === 'mothership') {
-      expect(liveRow.querySelector('[class*="shimmer"]')).toBeNull()
-    } else {
-      expect(liveRow.querySelector('[class*="shimmer"]')).not.toBeNull()
-    }
+    expect(liveRow.textContent).toBe('Reading second')
+    expect(liveRow.querySelector('[class*="shimmer"]')).not.toBeNull()
   })
 
-  it('distinguishes a finished tool from an open agent lane', () => {
+  it('keeps a finished tool in progress while its lane stays open', () => {
     render([tool('first')])
     advance(100)
     render([tool('first', 'success')])
-    expect(header()?.textContent).toBe(agentName === 'mothership' ? 'Read first' : 'Reading first')
-    if (agentName === 'mothership') {
-      expect(container.querySelector('[class*="shimmer"]')).toBeNull()
-    } else {
-      expect(container.querySelector('[class*="shimmer"]')).not.toBeNull()
-    }
+    expect(header()?.textContent).toBe('Reading first')
+    expect(container.querySelector('[class*="shimmer"]')).not.toBeNull()
     advance(1500)
-    expect(header()?.textContent).toBe(agentName === 'mothership' ? 'Read first' : 'Reading first')
+    expect(header()?.textContent).toBe('Reading first')
+    render([tool('first', 'success')], false)
+    expect(header()?.textContent).toBe('Read first')
+    expect(container.querySelector('[class*="shimmer"]')).toBeNull()
   })
 
   it('keeps the present-tense intent when expanded while completed collapse uses past tense', () => {
@@ -326,7 +321,7 @@ describe.each(['mothership', 'workflow', 'browser', 'deploy'])('%s activity', (a
         )
       )
     renderActivity('executing', true)
-    expect(header()?.textContent).toBe('Reading second + 1')
+    expect(header()?.textContent).toBe('Reading second')
     act(() => container.querySelector<HTMLElement>('[role="button"]')!.click())
     expect(header()?.textContent).toBe(activity.title)
     renderActivity('success', false)
@@ -363,7 +358,7 @@ describe.each(['mothership', 'workflow', 'browser', 'deploy'])('%s activity', (a
       }
     )
 
-    it('does not claim a merged activity completed when its unlabelled validation failed', () => {
+    it('does not claim an activity completed when its unlabelled validation failed', () => {
       const activity = {
         id: 'review',
         title: 'Reviewing invoices',
@@ -375,7 +370,6 @@ describe.each(['mothership', 'workflow', 'browser', 'deploy'])('%s activity', (a
             agentName='mothership'
             agentLabel='Sim'
             activity={activity}
-            completedGroupCount={2}
             items={items([
               { ...tool('read', 'success'), params: { activity: { id: 'first' } } },
               { ...tool('configure', 'success'), params: { activity } },
@@ -384,7 +378,7 @@ describe.each(['mothership', 'workflow', 'browser', 'deploy'])('%s activity', (a
           />
         )
       )
-      expect(header()?.textContent).toBe('Read configure + 1')
+      expect(header()?.textContent).toBe('Read files')
       expect(header()?.textContent).not.toContain(activity.completedTitle)
       act(() => container.querySelector<HTMLElement>('[role="button"]')!.click())
       expect(header()?.textContent).toBe(activity.title)
@@ -393,7 +387,7 @@ describe.each(['mothership', 'workflow', 'browser', 'deploy'])('%s activity', (a
       )
     })
 
-    it('shows active tool names and count, reserving the grouped completed title for lane closure', () => {
+    it('shows the active call without a count, reserving the completed title for lane closure', () => {
       const activity: ToolActivity = {
         id: 'research',
         title: 'Comparing files',
@@ -412,11 +406,11 @@ describe.each(['mothership', 'workflow', 'browser', 'deploy'])('%s activity', (a
           )
         )
       renderActivity([tool('first'), tool('second')], true)
-      expect(header()?.textContent).toBe('Reading second + 1')
+      expect(header()?.textContent).toBe('Reading second')
       expect(container.textContent).not.toContain(activity.completedTitle)
       renderActivity([tool('first', 'success'), tool('second', 'success')], true)
-      expect(header()?.textContent).toBe('Read second')
-      expect(container.querySelector('[class*="shimmer"]')).toBeNull()
+      expect(header()?.textContent).toBe('Reading second')
+      expect(container.querySelector('[class*="shimmer"]')).not.toBeNull()
       renderActivity([tool('first', 'success'), tool('second', 'success')], false)
       expect(header()?.textContent).toBe(activity.completedTitle)
       advance(2000)
@@ -448,8 +442,8 @@ describe.each(['mothership', 'workflow', 'browser', 'deploy'])('%s activity', (a
       renderActivity(true)
       expect(
         [...container.querySelectorAll('[role="status"]')].map((row) => row.textContent)
-      ).toEqual(['Read first', 'Read second'])
-      expect(container.querySelector('[class*="shimmer"]')).toBeNull()
+      ).toEqual(['Read first', 'Reading second'])
+      expect(container.querySelectorAll('[class*="shimmer"]')).toHaveLength(1)
       renderActivity(false)
       expect(
         [...container.querySelectorAll('[role="status"]')].map((row) => row.textContent)

apps/sim/app/workspace/[workspaceId]/home/components/message-content/components/agent-group/agent-group-view.tsx

@@ -6,7 +6,11 @@ import { isBrowserAgentAvailable } from '@/lib/browser-agent/transport'
 import type { ToolActivity } from '@/lib/mothership/generated/protocol'
 import { RETIRED_BROWSER_REQUEST_TAKEOVER_ID } from '@/lib/mothership/tools/retired-tools'
 import { readToolActivity } from '@/lib/mothership/tools/tool-activity'
-import { getToolDisplayTitle, getToolStatusDisplayTitle } from '@/lib/mothership/tools/tool-display'
+import {
+  getToolActiveTitle,
+  getToolDisplayTitle,
+  getToolStatusDisplayTitle,
+} from '@/lib/mothership/tools/tool-display'
 import { ActivityStream } from '@/app/workspace/[workspaceId]/home/components/message-content/components/agent-group/activity-stream'
 import {
   collectGroupTools,
@@ -19,6 +23,7 @@ import {
   getActiveToolActivityTitle,
   getActivityStatusTool,
   getToolActivitySummary,
+  isActivityStatusShimmering,
 } from '@/app/workspace/[workspaceId]/home/components/message-content/components/agent-group/tool-activity-group'
 import type { ToolCallItemProps } from '@/app/workspace/[workspaceId]/home/components/message-content/components/agent-group/tool-call-item'
 import {
@@ -54,7 +59,6 @@ export type AgentGroupItem =
 
 export interface AgentGroupProps {
   activity?: ToolActivity
-  completedGroupCount?: number
   error?: string
   agentName: string
   agentLabel: string
@@ -69,13 +73,15 @@ export interface AgentGroupProps {
   autoScrollActivity?: boolean
 }
 
+/** A working lane describes its latest call in progress, even after that call succeeded. */
 function activeToolTitle(tool: ToolCallData): string {
-  return getToolStatusDisplayTitle(
+  const title = getToolStatusDisplayTitle(
     tool.displayTitle || getToolDisplayTitle(String(tool.toolName ?? ''), undefined),
     tool.status === ToolCallStatus.success ? ToolCallStatus.executing : tool.status,
     tool.toolName,
     tool.activityDescription
   )
+  return tool.status === ToolCallStatus.success ? getToolActiveTitle(title) : title
 }
 
 /** Reveal blocking interactions even when a parent group was manually collapsed. */
@@ -148,7 +154,6 @@ export function AgentGroupView({
   agentName,
   agentLabel,
   activity: groupActivity,
-  completedGroupCount,
   error,
   items,
   isDelegating = false,
@@ -169,7 +174,6 @@ export function AgentGroupView({
       .map((tool) => readToolActivity(tool.params, tool.streamingArgs))
       .reverse()
       .find((entry) => entry?.title || entry?.completedTitle)
-  const runningCount = tools.filter((tool) => !isToolDone(tool.status)).length
   const resolved = isAgentGroupResolved(items)
   const browserAgentAvailable = isBrowserAgentAvailable()
   const activeBrowserTakeover =
@@ -253,7 +257,6 @@ export function AgentGroupView({
   const activity = isMainAgent ? (
     <MainAgentActivity
       activity={groupActivity}
-      completedGroupCount={completedGroupCount}
       items={items}
       ToolCallComponent={ToolCallComponent}
       renderItem={renderItem}
@@ -267,11 +270,7 @@ export function AgentGroupView({
     ? agentLabel
     : isWorking
       ? statusTool
-        ? getActiveToolActivityTitle(
-            `${activeToolTitle(statusTool)}${runningCount > 1 ? ` + ${runningCount - 1}` : ''}`,
-            statusTool,
-            tools
-          )
+        ? getActiveToolActivityTitle(activeToolTitle(statusTool), statusTool, tools)
         : 'Thinking'
       : activityDescriptor?.completedTitle &&
           tools.every((tool) => tool.status === ToolCallStatus.success)
@@ -280,11 +279,7 @@ export function AgentGroupView({
           ? getToolActivitySummary(tools)
           : agentLabel
   const headerActive =
-    !error &&
-    isWorking &&
-    (!statusTool ||
-      statusTool.status === ToolCallStatus.executing ||
-      statusTool.status === ToolCallStatus.success)
+    !error && isWorking && (!statusTool || isActivityStatusShimmering(statusTool))
   const collapsible =
     meaningfulItems.length > 1 ||
     meaningfulItems.some(