fix: circular import chat↔workspace — extract activityLog to activity.ts

web/src/lib/components/ActivityTimeline.svelte

@@ -1,5 +1,5 @@
 <script lang="ts">
-  import { activityLog, type ActivityEntry } from '$lib/stores/chat'
+  import { activityLog, type ActivityEntry } from '$lib/stores/activity'
   import LoaderCircleIcon from '@lucide/svelte/icons/loader-circle'
   import CircleCheckIcon from '@lucide/svelte/icons/circle-check'
   import CircleXIcon from '@lucide/svelte/icons/circle-x'

web/src/lib/components/AgentIndicator.svelte

@@ -1,5 +1,5 @@
 <script lang="ts">
-  import type { ActivityEntry } from '$lib/stores/chat'
+  import type { ActivityEntry } from '$lib/stores/activity'
   import LoaderCircleIcon from '@lucide/svelte/icons/loader-circle'
   import CheckIcon from '@lucide/svelte/icons/check'
   import XIcon from '@lucide/svelte/icons/x'

web/src/lib/components/TaskContextPanel.svelte

@@ -1,7 +1,8 @@
 <script lang="ts">
   import { onMount } from 'svelte'
   import { startWorkspace, planSteps, currentTask } from '$lib/stores/workspace'
-  import { activityLog, streaming } from '$lib/stores/chat'
+  import { activityLog } from '$lib/stores/activity'
+  import { streaming } from '$lib/stores/chat'
   import OperatorQuestion from './OperatorQuestion.svelte'
   import SessionGraph from './SessionGraph.svelte'
   import ActivityTimeline from './ActivityTimeline.svelte'