ZenUml · MrCoder · Jun 18, 2026 · Jun 14, 2026 · Jun 18, 2026 · Jun 18, 2026
diff --git a/e2e/tests/production-build.spec.js b/e2e/tests/production-build.spec.js
@@ -1,5 +1,5 @@
 import { test, expect } from '@playwright/test';
-import { existsSync, readdirSync } from 'fs';
+import { existsSync, readdirSync, readFileSync } from 'fs';
 
 // These tests check the LOCAL web/dist build and hit localhost:PREVIEW_PORT directly.
 // They must not run when PW_BASE_URL targets a remote host (staging/prod gate).
@@ -116,6 +116,43 @@ test('built dist serves the legacy privacy-policy and EULA legal pages', async (
   }
 });
 
+// Cutover regression guard: the rewrite shipped with NO favicon link (empty tab
+// icon, /favicon.ico 404) and no web manifest. This asserts the canonical favicon
+// + the PWA manifest and every icon it declares are served 200 from the built dist.
+test('built dist serves the favicon and a valid PWA manifest with resolvable icons', async ({
+  page,
+}) => {
+  // index.html must link the favicon + manifest (browsers fetch /favicon.ico
+  // otherwise → empty tab icon, the original regression).
+  const html = readFileSync(resolve(DIST, 'index.html'), 'utf8');
+  expect(html, 'built index.html lost its favicon <link rel="icon">').toMatch(
+    /rel="icon"/,
+  );
+  expect(html, 'built index.html lost its <link rel="manifest">').toMatch(
+    /rel="manifest"/,
+  );
+
+  // The manifest is served, valid, and every icon it declares resolves 200.
+  const manifestResp = await page.goto(`${PREVIEW_URL}manifest.webmanifest`);
+  expect(manifestResp?.status(), 'GET /manifest.webmanifest must be 200').toBe(
+    200,
+  );
+  const manifest = JSON.parse(await manifestResp.text());
+  expect(manifest.icons.length, 'manifest declares no icons').toBeGreaterThan(
+    0,
+  );
+  // A real installable PWA needs 192 + 512 PNG icons.
+  const pngSizes = manifest.icons
+    .filter((i) => i.type === 'image/png')
+    .map((i) => i.sizes);
+  expect(pngSizes).toEqual(expect.arrayContaining(['192x192', '512x512']));
+
+  for (const icon of manifest.icons) {
+    const r = await page.goto(`${PREVIEW_URL}${icon.src.replace(/^\//, '')}`);
+    expect(r?.status(), `manifest icon ${icon.src} must resolve 200`).toBe(200);
+  }
+});
+
 test('built app renders the diagram with no dev-only /@fs/ URL and a 200 core asset', async ({
   page,
 }) => {

diff --git a/web/index.html b/web/index.html
@@ -3,6 +3,15 @@
   <head>
     <meta charset="utf-8" />
     <meta name="viewport" content="width=device-width, initial-scale=1" />
+    <!-- Canonical ZenUML favicon (served from web/public). Without an icon link the
+         browser requests a non-existent /favicon.ico and shows an empty tab icon. -->
+    <link rel="icon" type="image/svg+xml" href="/zenuml-logo.svg" />
+    <link rel="icon" type="image/png" href="/favicon-128x128.png" />
+    <link rel="apple-touch-icon" href="/icon-192.png" />
+    <!-- PWA: web app manifest + theme color (icons rendered from BrandLogo artwork).
+         The legacy app shipped only an extension manifest; this is a real web manifest. -->
+    <link rel="manifest" href="/manifest.webmanifest" />
+    <meta name="theme-color" content="#2e94d4" />
     <title>ZenUML — Sequence Diagrams</title>
     <!-- Design system "Drafting Table": Hanken Grotesk (UI), IBM Plex Mono
          (code-adjacent metadata), Instrument Serif (editorial accents). -->

diff --git a/web/public/favicon-128x128.png b/web/public/favicon-128x128.png
diff --git a/web/public/icon-192.png b/web/public/icon-192.png
diff --git a/web/public/icon-512.png b/web/public/icon-512.png
diff --git a/web/public/icon-maskable-512.png b/web/public/icon-maskable-512.png
diff --git a/web/public/manifest.webmanifest b/web/public/manifest.webmanifest
@@ -0,0 +1,17 @@
+{
+  "name": "ZenUML Sequence",
+  "short_name": "ZenUML",
+  "description": "Real-time & offline tool for generating sequence diagrams",
+  "start_url": "/",
+  "scope": "/",
+  "display": "standalone",
+  "background_color": "#ffffff",
+  "theme_color": "#2e94d4",
+  "icons": [
+    { "src": "/favicon-128x128.png", "sizes": "128x128", "type": "image/png" },
+    { "src": "/icon-192.png", "sizes": "192x192", "type": "image/png", "purpose": "any" },
+    { "src": "/icon-512.png", "sizes": "512x512", "type": "image/png", "purpose": "any" },
+    { "src": "/icon-maskable-512.png", "sizes": "512x512", "type": "image/png", "purpose": "maskable" },
+    { "src": "/zenuml-logo.svg", "sizes": "any", "type": "image/svg+xml" }
+  ]
+}
diff --git a/web/public/zenuml-logo-maskable.svg b/web/public/zenuml-logo-maskable.svg