Cancel subscription sign-in requests when leaving agent setup (#19610)

Back during pending subscription sign-in could accept a late response and
reopen agent setup. Abort pending reads, release abandoned sessions, and
ignore stale responses. Wait for cleanup before starting a replacement,
and preserve sessions belonging to another account or environment.

Cover deferred resume/start/prompt responses for both providers, local
login cancellation, quick reselection, and browser request abort. Stabilize
Runner fixtures and normalization assertions exposed by integration CI.

Verified: 483 focused UI tests, six onboarding browser cases, UI typecheck
and token gates, Runner fixture checks, and the complete CI run on
221f2e3eb7. Greptile scored 5/5;
all review threads are resolved. Earlier failures and recovery evidence
remain in the PR description.

Co-Authored-By: Paperclip <noreply@paperclip.ing>

server/src/__tests__/agents-paperclip-runner-skills.test.ts

@@ -1,4 +1,5 @@
 import { describe, expect, it } from "vitest";
+import { PAPERCLIP_RUNNER_DEFAULT_MODELS } from "@paperclipai/adapter-utils/paperclip-runner-permissions";
 import {
   normalizePaperclipOperationalSkillPreference,
   normalizePaperclipRunnerAdapterConfig,
@@ -16,7 +17,7 @@ describe("paperclip_runner operational skill normalization", () => {
   it("applies full-auto native runner defaults at persistence boundaries", () => {
     expect(normalizePaperclipRunnerAdapterConfig("paperclip_runner", {})).toEqual({
       provider: "codex",
-      model: "gpt-5.6-sol",
+      model: PAPERCLIP_RUNNER_DEFAULT_MODELS.codex,
       codexPermissionMode: "never",
       lifecycleMode: "per_turn",
     });
@@ -24,7 +25,7 @@ describe("paperclip_runner operational skill normalization", () => {
 
   it("repairs an existing blank model without replacing an explicit model", () => {
     expect(normalizePaperclipRunnerAdapterConfig("paperclip_runner", { model: "" }))
-      .toMatchObject({ model: "gpt-5.6-sol" });
+      .toMatchObject({ model: PAPERCLIP_RUNNER_DEFAULT_MODELS.codex });
     expect(normalizePaperclipRunnerAdapterConfig("paperclip_runner", { model: "gpt-5.5" }))
       .toMatchObject({ model: "gpt-5.5" });
   });