diff --git a/packages/app/src/hooks/use-agent-history.ts b/packages/app/src/hooks/use-agent-history.ts
index 265a07cb1..1b17c5bee 100644
--- a/packages/app/src/hooks/use-agent-history.ts
+++ b/packages/app/src/hooks/use-agent-history.ts
@@ -126,10 +126,11 @@ export function useAgentHistory(options: {
     () =>
       (data?.pages ?? [])
         .flatMap((page) => page.agents)
-        .map((agent) => ({
-          ...agent,
-          serverLabel: serverLabel ?? agent.serverLabel,
-        })),
+        .map((agent) =>
+          Object.assign({}, agent, {
+            serverLabel: serverLabel ?? agent.serverLabel,
+          }),
+        ),
     [data?.pages, serverLabel],
   );
   const isInitialLoad = isLoading && agents.length === 0;
diff --git a/packages/app/src/stores/session-store-hooks.ts b/packages/app/src/stores/session-store-hooks.ts
index fb6a2f021..f6dd921aa 100644
--- a/packages/app/src/stores/session-store-hooks.ts
+++ b/packages/app/src/stores/session-store-hooks.ts
@@ -221,10 +221,9 @@ function selectWorkspaceStructureProjects(
     ({ workspaces: projectWorkspaces, ...project }) => {
       const sortedWorkspaces = [...projectWorkspaces].sort(compareWorkspaceStructureItems);
 
-      return {
-        ...project,
+      return Object.assign({}, project, {
         workspaceKeys: sortedWorkspaces.map((workspace) => workspace.workspaceId),
-      };
+      });
     },
   );
 
diff --git a/packages/app/src/stores/session-store.ts b/packages/app/src/stores/session-store.ts
index cd5c646c6..1d6d56352 100644
--- a/packages/app/src/stores/session-store.ts
+++ b/packages/app/src/stores/session-store.ts
@@ -135,7 +135,7 @@ export function normalizeWorkspaceDescriptor(
     name: payload.name,
     status: payload.status,
     diffStat: payload.diffStat ?? null,
-    scripts: (payload.scripts ?? []).map((s) => ({ ...s })),
+    scripts: (payload.scripts ?? []).map((s) => Object.assign({}, s)),
   };
 }
 
diff --git a/packages/app/src/stores/workspace-tabs-store.ts b/packages/app/src/stores/workspace-tabs-store.ts
index 5c3b7bbfd..c943dbb0e 100644
--- a/packages/app/src/stores/workspace-tabs-store.ts
+++ b/packages/app/src/stores/workspace-tabs-store.ts
@@ -277,7 +277,7 @@ export const useWorkspaceTabsStore = create<WorkspaceTabsState>()(
           }
 
           const nextTabs = currentTabs.map((tab, tabIndex) =>
-            tabIndex === index ? { ...tab, target: normalizedTarget } : tab,
+            tabIndex === index ? Object.assign({}, tab, { target: normalizedTarget }) : tab,
           );
           retargetedTabId = normalizedTabId;
           return {
diff --git a/packages/app/src/utils/provider-definitions.ts b/packages/app/src/utils/provider-definitions.ts
index c1b0b9a73..5ace4914a 100644
--- a/packages/app/src/utils/provider-definitions.ts
+++ b/packages/app/src/utils/provider-definitions.ts
@@ -9,11 +9,12 @@ import {
 function buildProviderModes(entry: ProviderSnapshotEntry): AgentProviderModeDefinition[] {
   const entryModes = entry.modes ?? [];
 
-  return entryModes.map((mode) => ({
-    ...mode,
-    icon: (mode.icon ?? "ShieldCheck") as AgentModeIcon,
-    colorTier: (mode.colorTier ?? "moderate") as AgentModeColorTier,
-  }));
+  return entryModes.map((mode) =>
+    Object.assign({}, mode, {
+      icon: (mode.icon ?? "ShieldCheck") as AgentModeIcon,
+      colorTier: (mode.colorTier ?? "moderate") as AgentModeColorTier,
+    }),
+  );
 }
 
 export function buildProviderDefinitions(
diff --git a/packages/server/src/server/agent/agent-manager.ts b/packages/server/src/server/agent/agent-manager.ts
index 480f43013..7e8a7236b 100644
--- a/packages/server/src/server/agent/agent-manager.ts
+++ b/packages/server/src/server/agent/agent-manager.ts
@@ -543,9 +543,7 @@ export class AgentManager {
   listAgents(): ManagedAgent[] {
     return Array.from(this.agents.values())
       .filter((agent) => !agent.internal)
-      .map((agent) => ({
-        ...agent,
-      }));
+      .map((agent) => Object.assign({}, agent));
   }
 
   async listPersistedAgents(
diff --git a/packages/server/src/server/agent/agent-projections.ts b/packages/server/src/server/agent/agent-projections.ts
index 66a4eae15..b793bcacb 100644
--- a/packages/server/src/server/agent/agent-projections.ts
+++ b/packages/server/src/server/agent/agent-projections.ts
@@ -294,13 +294,14 @@ function buildSerializableConfig(config: AgentSessionConfig): SerializableAgentC
 function sanitizePendingPermissions(
   pending: Map<string, AgentPermissionRequest>,
 ): AgentPermissionRequest[] {
-  return Array.from(pending.values()).map((request) => ({
-    ...request,
-    input: sanitizeMetadata(request.input),
-    suggestions: sanitizeMetadataArray(request.suggestions),
-    actions: request.actions?.map((action) => ({ ...action })),
-    metadata: sanitizeMetadata(request.metadata),
-  }));
+  return Array.from(pending.values()).map((request) =>
+    Object.assign({}, request, {
+      input: sanitizeMetadata(request.input),
+      suggestions: sanitizeMetadataArray(request.suggestions),
+      actions: request.actions?.map((action) => Object.assign({}, action)),
+      metadata: sanitizeMetadata(request.metadata),
+    }),
+  );
 }
 
 function sanitizePersistenceHandle(
diff --git a/packages/server/src/server/agent/provider-registry.ts b/packages/server/src/server/agent/provider-registry.ts
index 56c9f2d1e..5b149cb2f 100644
--- a/packages/server/src/server/agent/provider-registry.ts
+++ b/packages/server/src/server/agent/provider-registry.ts
@@ -271,12 +271,7 @@ function mergeModels(
   );
 
   return mergedModels.map((model) =>
-    additionalDefaultIds.has(model.id)
-      ? model
-      : {
-          ...model,
-          isDefault: false,
-        },
+    additionalDefaultIds.has(model.id) ? model : Object.assign({}, model, { isDefault: false }),
   );
 }
 
@@ -388,11 +383,10 @@ function createRegistryEntry(
         if (mode.icon && mode.colorTier) return mode;
         const definitionMode = resolved.definition.modes.find((d) => d.id === mode.id);
         if (!definitionMode) return mode;
-        return {
-          ...mode,
+        return Object.assign({}, mode, {
           icon: mode.icon ?? definitionMode.icon,
           colorTier: mode.colorTier ?? definitionMode.colorTier,
-        };
+        });
       });
     },
   };
diff --git a/packages/server/src/server/agent/providers/codex-app-server-agent.ts b/packages/server/src/server/agent/providers/codex-app-server-agent.ts
index 31bf97fb6..19927f53a 100644
--- a/packages/server/src/server/agent/providers/codex-app-server-agent.ts
+++ b/packages/server/src/server/agent/providers/codex-app-server-agent.ts
@@ -4379,10 +4379,11 @@ export class CodexAppServerAgentClient implements AgentClient {
           });
         }
 
-        const thinkingOptions = Array.from(thinkingById.values()).map((option) => ({
-          ...option,
-          isDefault: option.id === resolvedDefaultReasoningEffort,
-        }));
+        const thinkingOptions = Array.from(thinkingById.values()).map((option) =>
+          Object.assign({}, option, {
+            isDefault: option.id === resolvedDefaultReasoningEffort,
+          }),
+        );
         const defaultThinkingOptionId =
           resolvedDefaultReasoningEffort ??
           thinkingOptions.find((option) => option.isDefault)?.id ??
diff --git a/packages/server/src/server/script-proxy.ts b/packages/server/src/server/script-proxy.ts
index d15cf05f2..b16bf776c 100644
--- a/packages/server/src/server/script-proxy.ts
+++ b/packages/server/src/server/script-proxy.ts
@@ -106,7 +106,7 @@ export class ScriptRouteStore {
   }
 
   listRoutes(): ScriptRouteEntry[] {
-    return Array.from(this.routes.values()).map((entry) => ({ ...entry }));
+    return Array.from(this.routes.values()).map((entry) => Object.assign({}, entry));
   }
 
   listRoutesForWorkspace(workspaceId: string): ScriptRouteEntry[] {
diff --git a/packages/server/src/utils/worktree.ts b/packages/server/src/utils/worktree.ts
index 6267a5876..1340ddcab 100644
--- a/packages/server/src/utils/worktree.ts
+++ b/packages/server/src/utils/worktree.ts
@@ -1004,12 +1004,11 @@ export async function listPaseoWorktrees({
 
   const rootPrefix = normalizePathForOwnership(worktreesRoot) + sep;
   return parseWorktreeList(stdout)
-    .map((entry) => ({ ...entry, path: normalizePathForOwnership(entry.path) }))
+    .map((entry) => Object.assign({}, entry, { path: normalizePathForOwnership(entry.path) }))
     .filter((entry) => entry.path.startsWith(rootPrefix))
-    .map((entry) => ({
-      ...entry,
-      createdAt: resolveWorktreeCreatedAtIso(entry.path),
-    }));
+    .map((entry) =>
+      Object.assign({}, entry, { createdAt: resolveWorktreeCreatedAtIso(entry.path) }),
+    );
 }
 
 export async function resolveExistingWorktreeForSlug({
diff --git a/scripts/sync-release-notes-from-changelog.mjs b/scripts/sync-release-notes-from-changelog.mjs
index 30cb00a2b..70cee1615 100644
--- a/scripts/sync-release-notes-from-changelog.mjs
+++ b/scripts/sync-release-notes-from-changelog.mjs
@@ -109,11 +109,10 @@ function parseChangelog(changelogText) {
       notesParts.push("", ...bodyLines);
     }
 
-    return {
-      ...heading,
+    return Object.assign({}, heading, {
       tag: `v${heading.version}`,
       notes: `${notesParts.join("\n").trim()}\n`,
-    };
+    });
   });
 }