FN-6431: remove provider settings timeout appeasement

Keep provider-settings tests on Vitest's default timeout after fixture isolation fixes.

- Remove the file-wide 30s Vitest timeout override from provider-settings tests.
- Document why the synchronous temp-workspace checks must remain under the default timeout.

Files changed:
 .../cli/src/commands/__tests__/provider-settings.test.ts    | 13 +++++--------
 1 file changed, 5 insertions(+), 8 deletions(-)

Fusion-Task-Id: FN-6431

Fusion-Task-Lineage: 4e18795d-4cbb-4af7-92f7-8368cec95c37

packages/cli/src/commands/__tests__/provider-settings.test.ts

@@ -4,14 +4,11 @@ import { describe, expect, it, vi } from "vitest";
 import { tempWorkspace } from "@fusion/test-utils";
 import { createReadOnlyProviderSettingsView, createProjectSettingsPersistence } from "../provider-settings.js";
 
-// All tests here are pure synchronous FS operations against a temp workspace,
-// so they shouldn't take more than a handful of milliseconds. They have
-// occasionally tripped vitest's default 5s timeout when the worker pool is
-// starved by a parallel FS-heavy suite (one slot stalls long enough that the
-// runner gives up before the test body even gets a turn). Bumping the
-// per-test cap rules out worker contention as a flake source without
-// changing what the tests actually verify.
-vi.setConfig({ testTimeout: 30000 });
+/*
+FNXC:CliTests 2026-06-14-01:47:
+Provider-settings tests are synchronous temp-workspace filesystem checks, so they must stay on Vitest's default 5s timeout.
+FN-6431 removed the hidden file-wide 30s timeout appeasement after FN-6430 fixed the shared CLI fixture isolation path that previously caused package-load starvation.
+*/
 
 function writeJson(path: string, value: Record<string, unknown>): void {
   writeFileSync(path, JSON.stringify(value, null, 2));