feat: add Settings and Suite pages with comprehensive settings management and question suite builder

- Implemented SettingsPage for configuring default provider, temperature, and model paths.
- Added SuitePage for managing a suite of questions with features to add, edit, duplicate, and delete questions.
- Introduced TypeScript configuration files for app and node environments.
- Set up Vite configuration for development server with API proxying to backend.

web/src/components/Logo.tsx

@@ -0,0 +1,45 @@
+/** LM-Gambit brand mark — a chess pawn cut from a warm gradient. */
+
+import { useId } from 'react'
+
+export function Logo({ size = 30 }: { size?: number }) {
+  // The mark renders more than once per page (rail + mobile bar), so the
+  // gradient needs a unique id or the second instance resolves to the first.
+  const gradientId = useId()
+
+  return (
+    <svg
+      width={size}
+      height={size}
+      viewBox="0 0 40 40"
+      fill="none"
+      xmlns="http://www.w3.org/2000/svg"
+      aria-hidden="true"
+    >
+      <defs>
+        <linearGradient id={gradientId} x1="4" y1="2" x2="36" y2="38" gradientUnits="userSpaceOnUse">
+          <stop stopColor="#F4813F" />
+          <stop offset="1" stopColor="#E3AD46" />
+        </linearGradient>
+      </defs>
+      <rect x="1" y="1" width="38" height="38" rx="11" fill={`url(#${gradientId})`} />
+      <rect
+        x="1"
+        y="1"
+        width="38"
+        height="38"
+        rx="11"
+        stroke="#FFD9AE"
+        strokeOpacity="0.35"
+        strokeWidth="1.2"
+      />
+      {/* pawn silhouette */}
+      <path
+        d="M20 9.4a4 4 0 0 1 2.35 7.24c1.5.93 2.4 2.42 2.4 4.06 0 1.5-.74 2.86-1.96 3.79l1.9 6.7h-9.38l1.9-6.7a4.78 4.78 0 0 1-1.96-3.79c0-1.64.9-3.13 2.4-4.06A4 4 0 0 1 20 9.4Z"
+        fill="#160B04"
+        fillOpacity="0.82"
+      />
+      <rect x="12.4" y="29.4" width="15.2" height="3.4" rx="1.7" fill="#160B04" fillOpacity="0.82" />
+    </svg>
+  )
+}