Add animated glass background, breadcrumbs, and brand mark polish

Cards now sit on an animated signature-gradient background and use a
translucent, blurred bp-glass surface so it shines through; extended
bp-glass to every stat surface on the Stats page and to its tab switcher.
Adds a Breadcrumbs component below the header on all app pages.

Also: drop the gradient text fill from the wordmark/heading, animate the
BrandMark's heart and curve on the dashboard hero instead of a plain pulse
ring, recenter the heart/curve artwork in icon.svg and BrandMark, close the
mobile nav menu on link click, remove the redundant "back to recordings"
button, and match the "Start session"/"Scan for devices" button sizes.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

app/(app)/stats/page.tsx

@@ -27,7 +27,7 @@ export default async function StatsPage() {
       </div>
 
       <Tabs defaultValue="sessions">
-        <TabsList>
+        <TabsList className="bp-glass">
           <TabsTrigger value="sessions">Sessions</TabsTrigger>
           <TabsTrigger value="devices">Devices</TabsTrigger>
           <TabsTrigger value="recordings">Recordings</TabsTrigger>