feat(ui,infra): SvelteKit ui scaffold, Makefile, pre-commit, claude hooks

ui/: SvelteKit 2 + Svelte 5 + Tailwind 4 + shadcn-svelte (luma, lucide)
on bun with ultracite; adapter-static with SPA fallback; theme tokens
taken from msos. Dockerfile gains a bun stage that builds ui/build.
Makefile and pre-commit cover ruff, ty, ultracite and svelte-check;
.claude settings run the matching fixer after edits. docs/PRODUCT.md
captures product truth for the UI work.

ui/vite.config.ts

@@ -0,0 +1,19 @@
+import adapter from "@sveltejs/adapter-static";
+import { sveltekit } from "@sveltejs/kit/vite";
+import tailwindcss from "@tailwindcss/vite";
+import { defineConfig } from "vite";
+
+export default defineConfig({
+  plugins: [
+    tailwindcss(),
+    sveltekit({
+      adapter: adapter({ fallback: "index.html" }),
+      compilerOptions: {
+        // Force runes mode for the project, except for libraries. Can be removed in svelte 6.
+        runes: ({ filename }) =>
+          // biome-ignore lint/performance/useTopLevelRegex: svelte default
+          filename.split(/[/\\]/).includes("node_modules") ? undefined : true,
+      },
+    }),
+  ],
+});