fix(icon): wedding rings, and delete the skeleton favicon behind them

The event is a wedding, so the camera icon becomes two interlocking bands. Drawn rather
than sourced: at 16px in a tab anything finer than the stroke turns to smudge, which is
why the camera it replaces was three shapes and no more. White on #8a6a2b, the event's
own theme_primary, so the icon, the site and the PWA chrome finally agree -- the
manifest's theme_color was still the #2563eb from the camera branding.

The rings span x 88-424 and y 139-373 including stroke, inside the centre-80% safe zone,
so an Android circle crop cannot clip them.

Also removes a second, competing icon declaration. `+layout.svelte` imported
`$lib/assets/favicon.svg` -- the orange Svelte logo from the project skeleton, which Vite
inlined as a data URI into the layout bundle -- and applied it via `<svelte:head>`. Which
of the two won was left to the browser: the link in app.html is parsed from the initial
HTML, this one is added at hydration, and Chrome keeps the former. So the skeleton logo
did not usually show, but nothing guaranteed that, and `ssr = false` means the branded
link is the only one present at first paint anyway. app.html is now the single source and
the skeleton asset is gone.

frontend/src/lib/assets/favicon.svg

@@ -1 +0,0 @@
-<svg xmlns="http://www.w3.org/2000/svg" width="107" height="128" viewBox="0 0 107 128"><title>svelte-logo</title><path d="M94.157 22.819c-10.4-14.885-30.94-19.297-45.792-9.835L22.282 29.608A29.92 29.92 0 0 0 8.764 49.65a31.5 31.5 0 0 0 3.108 20.231 30 30 0 0 0-4.477 11.183 31.9 31.9 0 0 0 5.448 24.116c10.402 14.887 30.942 19.297 45.791 9.835l26.083-16.624A29.92 29.92 0 0 0 98.235 78.35a31.53 31.53 0 0 0-3.105-20.232 30 30 0 0 0 4.474-11.182 31.88 31.88 0 0 0-5.447-24.116" style="fill:#ff3e00"/><path d="M45.817 106.582a20.72 20.72 0 0 1-22.237-8.243 19.17 19.17 0 0 1-3.277-14.503 18 18 0 0 1 .624-2.435l.49-1.498 1.337.981a33.6 33.6 0 0 0 10.203 5.098l.97.294-.09.968a5.85 5.85 0 0 0 1.052 3.878 6.24 6.24 0 0 0 6.695 2.485 5.8 5.8 0 0 0 1.603-.704L69.27 76.28a5.43 5.43 0 0 0 2.45-3.631 5.8 5.8 0 0 0-.987-4.371 6.24 6.24 0 0 0-6.698-2.487 5.7 5.7 0 0 0-1.6.704l-9.953 6.345a19 19 0 0 1-5.296 2.326 20.72 20.72 0 0 1-22.237-8.243 19.17 19.17 0 0 1-3.277-14.502 17.99 17.99 0 0 1 8.13-12.052l26.081-16.623a19 19 0 0 1 5.3-2.329 20.72 20.72 0 0 1 22.237 8.243 19.17 19.17 0 0 1 3.277 14.503 18 18 0 0 1-.624 2.435l-.49 1.498-1.337-.98a33.6 33.6 0 0 0-10.203-5.1l-.97-.294.09-.968a5.86 5.86 0 0 0-1.052-3.878 6.24 6.24 0 0 0-6.696-2.485 5.8 5.8 0 0 0-1.602.704L37.73 51.72a5.42 5.42 0 0 0-2.449 3.63 5.79 5.79 0 0 0 .986 4.372 6.24 6.24 0 0 0 6.698 2.486 5.8 5.8 0 0 0 1.602-.704l9.952-6.342a19 19 0 0 1 5.295-2.328 20.72 20.72 0 0 1 22.237 8.242 19.17 19.17 0 0 1 3.277 14.503 18 18 0 0 1-8.13 12.053l-26.081 16.622a19 19 0 0 1-5.3 2.328" style="fill:#fff"/></svg>

frontend/src/routes/+layout.svelte

@@ -1,5 +1,4 @@
 <script lang="ts">
-	import favicon from '$lib/assets/favicon.svg';
 	import '../app.css';
 	import { initAuth, getToken, getUserId, clearPin } from '$lib/auth';
 	import { initTheme } from '$lib/theme-store';
@@ -227,9 +226,11 @@
 	});
 </script>
 
-<svelte:head>
-	<link rel="icon" href={favicon} />
-</svelte:head>
+<!-- NO `<svelte:head><link rel="icon">` here. There used to be one, pointing at
+     `$lib/assets/favicon.svg` — the orange Svelte logo from the project skeleton. Vite inlined it
+     as a data URI into the layout bundle and this block applied it AFTER hydration, so it beat the
+     branded `<link rel="icon">` in app.html and the tab showed the framework's logo on every page.
+     app.html is now the single source for the icon; the skeleton asset is deleted. -->
 
 {@render children()}