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>

components/layout/BrandMark.tsx

@@ -3,10 +3,12 @@ import { cn } from "@/lib/utils";
 interface BrandMarkProps {
   size?: number;
   className?: string;
+  /** Beats the heart glyph and makes the curve glow - used for the dashboard hero mark. */
+  animated?: boolean;
 }
 
 /** Inline twin of app/icon.svg (the favicon) - kept as markup, not an <img>, so it can be sized/animated with CSS. */
-export function BrandMark({ size = 28, className }: BrandMarkProps) {
+export function BrandMark({ size = 28, className, animated = false }: BrandMarkProps) {
   return (
     <svg
       width={size}
@@ -25,18 +27,22 @@ export function BrandMark({ size = 28, className }: BrandMarkProps) {
         </linearGradient>
       </defs>
       <rect x="1" y="1" width="30" height="30" rx="9" fill="url(#bpGradMark)" />
-      <path
-        d="M16 22.6c-.3 0-.5-.1-.7-.3C11.7 19 8 15.6 8 12.3 8 9.9 9.9 8 12.3 8c1.3 0 2.6.6 3.4 1.7.1.1.2.1.3 0 .8-1.1 2.1-1.7 3.4-1.7C21.8 8 23.7 9.9 23.7 12.3c0 3.3-3.7 6.7-7.3 10-.2.2-.4.3-.7.3z"
-        fill="rgba(255,255,255,0.22)"
-      />
-      <polyline
-        points="6,15 10,15 12,9 15,21 18,13 20,15 26,15"
-        fill="none"
-        stroke="#ffffff"
-        strokeWidth={1.7}
-        strokeLinecap="round"
-        strokeLinejoin="round"
-      />
+      <g transform="translate(0 0.7)">
+        <path
+          d="M16 22.6c-.3 0-.5-.1-.7-.3C11.7 19 8 15.6 8 12.3 8 9.9 9.9 8 12.3 8c1.3 0 2.6.6 3.4 1.7.1.1.2.1.3 0 .8-1.1 2.1-1.7 3.4-1.7C21.8 8 23.7 9.9 23.7 12.3c0 3.3-3.7 6.7-7.3 10-.2.2-.4.3-.7.3z"
+          fill="rgba(255,255,255,0.22)"
+          className={cn(animated && "bp-mark-heart")}
+        />
+        <polyline
+          points="6,15 10,15 12,9 15,21 18,13 20,15 26,15"
+          fill="none"
+          stroke="#ffffff"
+          strokeWidth={1.7}
+          strokeLinecap="round"
+          strokeLinejoin="round"
+          className={cn(animated && "bp-mark-curve")}
+        />
+      </g>
     </svg>
   );
 }