test(frontend): extract resolveSessionDryRun to helper + add coverage

- Extract session dry_run resolution logic from useChatSession.ts into
  resolveSessionDryRun() helper in helpers.ts for testability
- Add 6 unit tests covering null/undefined/non-200/false/missing/true
  branches of resolveSessionDryRun in __tests__/helpers.test.ts
- Remove unused isDryRun destructure from CopilotPage.tsx (now only
  sessionDryRun is used for the session-scoped test mode banner)
- Fix patch coverage gap: new sessionDryRun logic is now fully covered

autogpt_platform/frontend/src/app/(platform)/copilot/CopilotPage.tsx

@@ -113,8 +113,7 @@ export function CopilotPage() {
     // Rate limit reset
     rateLimitMessage,
     dismissRateLimit,
-    // Dry run dev toggle
-    isDryRun,
+    // Dry run session state
     sessionDryRun,
   } = useCopilotPage();
 

autogpt_platform/frontend/src/app/(platform)/copilot/__tests__/helpers.test.ts

@@ -1,6 +1,6 @@
 import { beforeEach, describe, expect, it, vi } from "vitest";
 import { IMPERSONATION_HEADER_NAME } from "@/lib/constants";
-import { getCopilotAuthHeaders } from "../helpers";
+import { getCopilotAuthHeaders, resolveSessionDryRun } from "../helpers";
 
 vi.mock("@/lib/supabase/actions", () => ({
   getWebSocketToken: vi.fn(),
@@ -16,6 +16,42 @@ import { getSystemHeaders } from "@/lib/impersonation";
 const mockGetWebSocketToken = vi.mocked(getWebSocketToken);
 const mockGetSystemHeaders = vi.mocked(getSystemHeaders);
 
+describe("resolveSessionDryRun", () => {
+  it("returns false when queryData is null", () => {
+    expect(resolveSessionDryRun(null)).toBe(false);
+  });
+
+  it("returns false when queryData is undefined", () => {
+    expect(resolveSessionDryRun(undefined)).toBe(false);
+  });
+
+  it("returns false when status is not 200", () => {
+    expect(resolveSessionDryRun({ status: 404 })).toBe(false);
+  });
+
+  it("returns false when status is 200 but metadata.dry_run is false", () => {
+    expect(
+      resolveSessionDryRun({
+        status: 200,
+        data: { metadata: { dry_run: false } },
+      }),
+    ).toBe(false);
+  });
+
+  it("returns false when status is 200 but metadata is missing", () => {
+    expect(resolveSessionDryRun({ status: 200, data: {} })).toBe(false);
+  });
+
+  it("returns true when status is 200 and metadata.dry_run is true", () => {
+    expect(
+      resolveSessionDryRun({
+        status: 200,
+        data: { metadata: { dry_run: true } },
+      }),
+    ).toBe(true);
+  });
+});
+
 describe("getCopilotAuthHeaders", () => {
   beforeEach(() => {
     vi.clearAllMocks();

autogpt_platform/frontend/src/app/(platform)/copilot/helpers.ts

@@ -52,6 +52,24 @@ export function parseSessionIDs(raw: string | null | undefined): Set<string> {
   }
 }
 
+/**
+ * Resolve the actual dry_run value for a session from the raw API response.
+ * Returns true only when the session response is a 200 with metadata.dry_run === true.
+ * Returns false for missing/non-200 responses so callers never show a stale
+ * preference value when the real session state is unknown.
+ */
+export function resolveSessionDryRun(queryData: unknown): boolean {
+  if (
+    queryData == null ||
+    typeof queryData !== "object" ||
+    !("status" in queryData) ||
+    (queryData as { status: unknown }).status !== 200
+  )
+    return false;
+  const d = queryData as { data?: { metadata?: { dry_run?: unknown } } };
+  return d.data?.metadata?.dry_run === true;
+}
+
 /**
  * Check whether a refetchSession result indicates the backend still has an
  * active SSE stream for this session.

autogpt_platform/frontend/src/app/(platform)/copilot/useChatSession.ts

@@ -10,6 +10,7 @@ import { useQueryClient } from "@tanstack/react-query";
 import { parseAsString, useQueryState } from "nuqs";
 import { useEffect, useMemo, useRef } from "react";
 import { convertChatSessionMessagesToUiMessages } from "./helpers/convertChatSessionToUiMessages";
+import { resolveSessionDryRun } from "./helpers";
 
 interface UseChatSessionOptions {
   dryRun?: boolean;
@@ -170,10 +171,10 @@ export function useChatSession({ dryRun = false }: UseChatSessionOptions = {}) {
   // Design intent: the global isDryRun store is only used when creating NEW
   // sessions. Once a session exists, its dry_run flag is immutable and should
   // be read from here rather than from the store, which may have changed.
-  const sessionDryRun = useMemo(() => {
-    if (sessionQuery.data?.status !== 200) return false;
-    return sessionQuery.data.data.metadata?.dry_run === true;
-  }, [sessionQuery.data]);
+  const sessionDryRun = useMemo(
+    () => resolveSessionDryRun(sessionQuery.data),
+    [sessionQuery.data],
+  );
 
   return {
     sessionId,