Keep large sidebars responsive (#1966)

* perf(app): keep large sidebars responsive

Sidebar rows rescanned every agent for each session update, multiplying work with both workspace and agent count. Build workspace activity once and share the derived sidebar model so updates scale with the underlying collections.

* test(app): use valid agent fixture for workspace restore

* refactor(app): keep sidebar model surface focused

packages/app/src/hooks/sidebar-workspaces-view-model.ts

@@ -2,13 +2,13 @@ import type { PrHint } from "@/git/pr-hint";
 import { selectPrHintFromStatus } from "@/git/pr-hint";
 import { type HostProjectListItem } from "@/projects/host-project-model";
 import type { PendingCreateAttempt } from "@/stores/create-flow-store";
-import type { Agent, WorkspaceDescriptor } from "@/stores/session-store";
+import type { WorkspaceDescriptor } from "@/stores/session-store";
 import type {
   WorkspaceStructureHostPlacement,
   WorkspaceStructureProject,
 } from "@/projects/workspace-structure";
 import { projectDisplayNameFromProjectId } from "@/utils/project-display-name";
-import { deriveSidebarStateBucket } from "@/utils/sidebar-agent-state";
+import type { WorkspaceAgentActivity } from "@/utils/workspace-agent-activity";
 import { resolveWorkspaceMapKeyByIdentity } from "@/utils/workspace-identity";
 
 const EMPTY_PROJECTS: SidebarProjectEntry[] = [];
@@ -66,7 +66,7 @@ export interface SidebarWorkspacePlacementModel {
 export interface SidebarStatusWorkspaceSession {
   serverId: string;
   workspaces: Map<string, WorkspaceDescriptor>;
-  agents?: Map<string, Agent>;
+  workspaceAgentActivity: Map<string, WorkspaceAgentActivity>;
 }
 
 interface EffectiveWorkspaceStatus {
@@ -74,8 +74,6 @@ interface EffectiveWorkspaceStatus {
   enteredAt: Date | null;
 }
 
-interface WorkspaceAgentActivity extends EffectiveWorkspaceStatus {}
-
 function projectNameForWorkspace(workspace: WorkspaceDescriptor, projectKey: string): string {
   return (
     workspace.projectCustomName ??
@@ -96,7 +94,7 @@ export function createSidebarWorkspaceEntry(input: {
   serverId: string;
   workspace: WorkspaceDescriptor;
   pendingCreateAttempts?: Record<string, PendingCreateAttempt>;
-  agents?: Map<string, Agent>;
+  workspaceAgentActivity?: ReadonlyMap<string, WorkspaceAgentActivity>;
 }): SidebarWorkspaceEntry {
   const projectKey = input.workspace.project?.projectKey ?? input.workspace.projectId;
   const effectiveStatus = deriveEffectiveWorkspaceStatus(input);
@@ -129,7 +127,7 @@ function deriveEffectiveWorkspaceStatus(input: {
   serverId: string;
   workspace: WorkspaceDescriptor;
   pendingCreateAttempts?: Record<string, PendingCreateAttempt>;
-  agents?: Map<string, Agent>;
+  workspaceAgentActivity?: ReadonlyMap<string, WorkspaceAgentActivity>;
 }): EffectiveWorkspaceStatus {
   if (input.workspace.status !== "done") {
     return { status: input.workspace.status, enteredAt: input.workspace.statusEnteredAt };
@@ -144,10 +142,7 @@ function deriveEffectiveWorkspaceStatus(input: {
     return { status: "running", enteredAt: pendingStartedAt };
   }
 
-  const rootAgentActivity = getRootAgentWorkspaceActivity({
-    workspace: input.workspace,
-    agents: input.agents,
-  });
+  const rootAgentActivity = input.workspaceAgentActivity?.get(input.workspace.id);
   if (rootAgentActivity && rootAgentActivity.status !== "done") {
     return rootAgentActivity;
   }
@@ -173,28 +168,6 @@ function getPendingInitialAgentCreateStartedAt(input: {
   return latestStartedAt;
 }
 
-function getRootAgentWorkspaceActivity(input: {
-  workspace: WorkspaceDescriptor;
-  agents?: Map<string, Agent>;
-}): WorkspaceAgentActivity | null {
-  let latest: WorkspaceAgentActivity | null = null;
-  for (const agent of input.agents?.values() ?? []) {
-    if (agent.archivedAt || agent.parentAgentId) continue;
-    if (agent.workspaceId !== input.workspace.id) continue;
-    const status = deriveSidebarStateBucket({
-      status: agent.status,
-      pendingPermissionCount: agent.pendingPermissions.length,
-      requiresAttention: agent.requiresAttention,
-      attentionReason: agent.attentionReason,
-    });
-    const enteredAt = agent.attentionTimestamp ?? agent.updatedAt;
-    if (!latest || enteredAt > (latest.enteredAt ?? new Date(0))) {
-      latest = { status, enteredAt };
-    }
-  }
-  return latest;
-}
-
 export function buildSidebarWorkspacePlacementModel(input: {
   projects: readonly HostProjectListItem[];
 }): SidebarWorkspacePlacementModel {
@@ -298,7 +271,7 @@ export function buildSidebarStatusWorkspacePlacements(input: {
       serverId: placement.serverId,
       workspace,
       pendingCreateAttempts: input.pendingCreateAttempts,
-      agents: session.agents,
+      workspaceAgentActivity: session.workspaceAgentActivity,
     });
 
     rows.push({