Scaffold Svelte frontend and browser test matrix

Establish the TypeScript 7, Oxlint, Vitest, and Playwright workspace with an isolated Svelte diagnostics compatibility boundary.

web/src/App.svelte

@@ -0,0 +1,55 @@
+<script lang="ts">
+  import { applicationName } from './lib/application'
+</script>
+
+<svelte:head>
+  <title>{applicationName}</title>
+</svelte:head>
+
+<main>
+  <p>Durable transfer service</p>
+  <h1>{applicationName}</h1>
+</main>
+
+<style>
+  :global(*) {
+    box-sizing: border-box;
+  }
+
+  :global(body) {
+    margin: 0;
+    min-width: 20rem;
+    min-height: 100vh;
+    color: #14213d;
+    background: #f8f7f2;
+    font-family:
+      Inter,
+      ui-sans-serif,
+      system-ui,
+      -apple-system,
+      BlinkMacSystemFont,
+      sans-serif;
+  }
+
+  main {
+    display: grid;
+    min-height: 100vh;
+    place-content: center;
+    padding: 2rem;
+    text-align: center;
+  }
+
+  p {
+    margin: 0;
+    color: #52606d;
+    font-size: 0.875rem;
+    letter-spacing: 0.12em;
+    text-transform: uppercase;
+  }
+
+  h1 {
+    margin: 0.5rem 0 0;
+    font-size: clamp(3rem, 12vw, 7rem);
+    letter-spacing: -0.06em;
+  }
+</style>