MAESTRO: add browser cache e2e test

Auto Run Docs/SpecKit-web-header-analyzer-Phase-10-Playwright-E2E.md

@@ -73,7 +73,7 @@ All tasks in this phase are parallelizable [P] since they are independent E2E sp
 - [x] T056 [P] Create `frontend/e2e/file-drop.spec.ts` — test US1 file drop flow: dispatch synthetic DataTransfer+drop events on drop zone with `.eml` fixture → verify textarea auto-populates with header content → click Analyse → verify report renders. Test rejection of unsupported file types (e.g., `.pdf`)
 - [x] T057 [P] Create `frontend/e2e/test-selection.spec.ts` — test US2: open test selector → verify 106+ tests listed → click Deselect All → select 3 specific tests → analyse → verify only 3 results in report. Test search/filter narrows visible tests. Test DNS and decode-all toggle states persist through analysis
 - [x] T058 [P] Create `frontend/e2e/report-interaction.spec.ts` — test US4 report features: expand all cards → collapse all → search for a term → verify filtered results → clear search → export JSON → verify downloaded file is valid JSON. Export HTML → verify downloaded file contains styled content
-- [ ] T059 [P] Create `frontend/e2e/browser-cache.spec.ts` — test US5: complete analysis → reload page → verify headers and results restored from cache → click Clear Cache → verify input and report cleared → reload → verify empty state
+- [x] T059 [P] Create `frontend/e2e/browser-cache.spec.ts` — test US5: complete analysis → reload page → verify headers and results restored from cache → click Clear Cache → verify input and report cleared → reload → verify empty state
 - [ ] T060 [P] Create `frontend/e2e/rate-limiting.spec.ts` — test US6 rate limiting flow: submit requests until 429 response → verify CAPTCHA modal appears → solve CAPTCHA → verify bypass token stored → retry original request succeeds. Test that the CAPTCHA modal is keyboard accessible and visually correct
 - [ ] T061 [P] Create `frontend/e2e/visual-regression.spec.ts` — screenshot-based visual testing at 4 viewports (320×568, 768×1024, 1280×720, 2560×1080). Capture: landing page (empty state), landing page with headers pasted, progress indicator active, report view with results expanded, hop chain visualisation. Use `expect(page).toHaveScreenshot()` with `animations: 'disabled'` and `mask` for dynamic content (timestamps, elapsed time). Baselines stored in `frontend/e2e/__snapshots__/`
 - [ ] T062 [P] Create `frontend/e2e/accessibility.spec.ts` — WCAG 2.1 AA audit using `@axe-core/playwright`. Run `AxeBuilder({ page }).withTags(['wcag2a', 'wcag2aa', 'wcag21aa']).analyze()` on: landing page (empty), landing page with input, report view, CAPTCHA modal (if rate-limited). Assert zero violations. Document any necessary exceptions with justification

frontend/e2e/browser-cache.spec.ts

@@ -0,0 +1,47 @@
+import { test, expect } from "@playwright/test";
+import fs from "fs/promises";
+import path from "path";
+
+import { AnalyzerPage } from "./pages/analyzer-page";
+
+const headersPath = path.resolve(__dirname, "fixtures/sample-headers.txt");
+
+test("browser cache restores analysis and clears on demand", async ({ page }) => {
+  const headers = await fs.readFile(headersPath, "utf8");
+  const analyzer = new AnalyzerPage(page);
+
+  await analyzer.goto();
+  await analyzer.pasteHeaders(headers);
+  await analyzer.clickAnalyse();
+  await analyzer.waitForResults();
+
+  const headerInput = page.getByRole("textbox", { name: "Header Input" });
+  const reportContainer = page.getByTestId("report-container");
+
+  await expect(headerInput).toHaveValue(headers);
+  await expect(reportContainer).toBeVisible();
+
+  await page.reload();
+
+  await expect(headerInput).toHaveValue(headers);
+  await expect(reportContainer).toBeVisible();
+  await expect(page.getByText("Cached Result")).toBeVisible();
+
+  const clearCacheButton = page.getByRole("button", { name: "Clear Cache" });
+  await expect(clearCacheButton).toBeEnabled();
+  await analyzer.clearCache();
+
+  await expect(headerInput).toHaveValue("");
+  await expect(page.getByTestId("report-container")).toHaveCount(0);
+  await expect(page.getByText("Cached Result")).toHaveCount(0);
+  await expect(clearCacheButton).toBeDisabled();
+  await expect(
+    page.getByText("No cached analysis yet. Run an analysis to save this session."),
+  ).toBeVisible();
+
+  await page.reload();
+
+  await expect(headerInput).toHaveValue("");
+  await expect(page.getByTestId("report-container")).toHaveCount(0);
+  await expect(page.getByText("Cached Result")).toHaveCount(0);
+});