feat(branding): replace placeholder brand icon with official logo icons

frontend/public/manifest.webmanifest

@@ -13,13 +13,61 @@
   "categories": ["business", "finance", "productivity"],
   "icons": [
     {
-      "src": "/icons/icon-192.png",
+      "src": "/icons/icon-48x48.png",
+      "sizes": "48x48",
+      "type": "image/png",
+      "purpose": "any"
+    },
+    {
+      "src": "/icons/icon-72x72.png",
+      "sizes": "72x72",
+      "type": "image/png",
+      "purpose": "any"
+    },
+    {
+      "src": "/icons/icon-96x96.png",
+      "sizes": "96x96",
+      "type": "image/png",
+      "purpose": "any"
+    },
+    {
+      "src": "/icons/icon-128x128.png",
+      "sizes": "128x128",
+      "type": "image/png",
+      "purpose": "any"
+    },
+    {
+      "src": "/icons/icon-144x144.png",
+      "sizes": "144x144",
+      "type": "image/png",
+      "purpose": "any"
+    },
+    {
+      "src": "/icons/icon-152x152.png",
+      "sizes": "152x152",
+      "type": "image/png",
+      "purpose": "any"
+    },
+    {
+      "src": "/icons/icon-192x192.png",
       "sizes": "192x192",
       "type": "image/png",
       "purpose": "any"
     },
     {
-      "src": "/icons/icon-512.png",
+      "src": "/icons/icon-256x256.png",
+      "sizes": "256x256",
+      "type": "image/png",
+      "purpose": "any"
+    },
+    {
+      "src": "/icons/icon-384x384.png",
+      "sizes": "384x384",
+      "type": "image/png",
+      "purpose": "any"
+    },
+    {
+      "src": "/icons/icon-512x512.png",
       "sizes": "512x512",
       "type": "image/png",
       "purpose": "any"

frontend/src/app/app.ts

@@ -54,7 +54,14 @@ const NAV: NavItem[] = [
           aria-label="Main"
         >
           <div class="mb-6 flex items-center gap-2">
-            <span class="bg-brand-teal size-7 rounded-lg" aria-hidden="true"></span>
+            <img
+              src="/icons/icon-96x96.png"
+              alt=""
+              width="28"
+              height="28"
+              class="size-7 rounded-lg"
+              aria-hidden="true"
+            />
             <span class="font-display text-lg">Actuo</span>
           </div>
 

frontend/src/app/pages/landing/landing.ts

@@ -17,7 +17,14 @@ import { RouterLink } from '@angular/router';
   template: `
     <div class="min-h-dvh bg-canvas text-body">
       <header class="mx-auto flex max-w-5xl items-center gap-3 px-5 py-5">
-        <span class="bg-brand-teal size-8 rounded-lg" aria-hidden="true"></span>
+        <img
+          src="/icons/icon-96x96.png"
+          alt=""
+          width="32"
+          height="32"
+          class="size-8 rounded-lg"
+          aria-hidden="true"
+        />
         <span class="font-display text-xl">Actuo</span>
         <nav class="ml-auto flex items-center gap-2" aria-label="Account">
           <a routerLink="/login" class="flex min-h-11 items-center px-3 text-muted hover:text-body">