docs(FN-3293): finalize stabilization audit documentation

- Add FN-3293 stabilization update section to docs/test-audit-report.md
- Document deterministic test hardening across CLI, dashboard, droid-cli, and core suites
- Update flaky hotspot notes to reflect resolved dashboard retry timeout coverage

Fusion-Task-Id: FN-3293

packages/droid-cli/src/__tests__/provider.test.ts

@@ -147,7 +147,7 @@ describe("provider registration (default export)", () => {
   });
 });
 
-describe("streamViaCli", { timeout: 90_000 }, () => {
+describe("streamViaCli", () => {
   beforeEach(() => {
     vi.clearAllMocks();
     vi.useFakeTimers({ toFake: ["setTimeout", "clearTimeout"] });