feat(pwa): blue splash screen with the logo, status bar follows the theme

Manifest: short name, blue background/theme colour for the Android splash.
index.html shows a plain blue screen with the logo until React mounts.
theme-color starts blue and then follows the active theme background.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

frontend/index.html

@@ -3,7 +3,8 @@
   <head>
     <meta charset="UTF-8" />
     <meta name="viewport" content="width=device-width, initial-scale=1.0, maximum-scale=1.0, user-scalable=no" />
-    <meta name="theme-color" content="#0b0f19" />
+    <!-- Blue while loading (matches the splash screen); the app switches it to the theme background -->
+    <meta name="theme-color" content="#2563eb" />
     <meta name="mobile-web-app-capable" content="yes" />
     <meta name="apple-mobile-web-app-capable" content="yes" />
     <meta name="apple-mobile-web-app-title" content="MindSift" />
@@ -49,7 +50,13 @@
     </script>
   </head>
   <body class="bg-[#0b0f19] text-[#e3e3e3] antialiased selection:bg-[#8ab4f8]/30 selection:text-[#8ab4f8]">
-    <div id="root"></div>
+    <!-- Shown until React mounts and replaces it: full blue with the logo, no text, no white flash -->
+    <div id="root">
+      <div style="position:fixed;inset:0;background:#2563eb;display:flex;align-items:center;justify-content:center">
+        <!-- the icon's own blue square disappears on blue, so the visible brain is ~55% of this size -->
+        <img src="/icon.svg" width="128" height="128" alt="" style="display:block" />
+      </div>
+    </div>
     <script type="module" src="/src/main.tsx"></script>
     <script>
       if ('caches' in window) {

frontend/public/manifest.json

@@ -1,13 +1,13 @@
 {
   "id": "/",
-  "name": "MindSift — Der Kopf frei in drei Sekunden",
+  "name": "MindSift",
   "short_name": "MindSift",
-  "description": "Instant Brain-Dump, Tinder-Style Triage, Workspace & Echtzeit-Familienlisten.",
+  "description": "MindSift — Der Kopf frei in drei Sekunden. Instant Brain-Dump, Tinder-Style Triage, Workspace & Echtzeit-Familienlisten.",
   "start_url": "/",
   "scope": "/",
   "display": "standalone",
-  "background_color": "#0b0f19",
-  "theme_color": "#0b0f19",
+  "background_color": "#2563eb",
+  "theme_color": "#2563eb",
   "orientation": "portrait-primary",
   "icons": [
     {

frontend/src/lib/theme.ts

@@ -132,6 +132,18 @@ function applyToDocument(themeId: ThemeId, customCss: string | null): void {
   root.setAttribute('data-theme', attr);
   const light = customCss !== null ? isLightColor(readCssVar(customCss, 'bg-app')) : themeId === 'light';
   root.classList.toggle('dark', !light);
+  syncThemeColorMeta();
+}
+
+// The status bar (theme-color) starts blue for the splash screen; once the app runs it follows the
+// active theme's background so it blends with the header.
+function syncThemeColorMeta(): void {
+  const meta = document.querySelector('meta[name="theme-color"]');
+  if (!meta || typeof requestAnimationFrame === 'undefined') return;
+  requestAnimationFrame(() => {
+    const bg = getComputedStyle(document.documentElement).getPropertyValue('--bg-app').trim();
+    if (bg) meta.setAttribute('content', bg);
+  });
 }
 
 function store(key: string, value: string | null): void {