chore(frontend): unbreak the shared-utils library build (#10734)

Co-authored-by: Claude Opus 5 (1M context) <noreply@anthropic.com>

frontend/sharedUtils/vite.sharedUtils.config.js

@@ -1,11 +1,12 @@
 import { defineConfig } from 'vite'
+import { svelte } from '@sveltejs/vite-plugin-svelte'
 import { resolve } from 'path'
 import { writeFileSync } from 'fs'
 import { exec } from 'child_process'
 import { promisify } from 'util'
 
 const execAsync = promisify(exec)
-const VERSION = '1.0.12'
+const VERSION = '1.0.13'
 
 export default defineConfig({
 	build: {
@@ -24,6 +25,7 @@ export default defineConfig({
 		}
 	},
 	plugins: [
+		svelte(),
 		{
 			name: 'bundle-types',
 			async closeBundle() {

frontend/src/lib/svelte5Utils.svelte.ts

@@ -18,8 +18,12 @@ export function createState<T>(initialValue: T): T {
 	return s
 }
 
-export function stateSnapshot<T>(state: T) {
-	return $state.snapshot(state)
+// Annotated: the inferred `Snapshot<T>` is a deep conditional type TS refuses to
+// serialize into a declaration file (TS7056), which breaks the shared-utils build.
+// `Snapshot<T>` is not exported from the `$state` namespace, and it only differs
+// from `T` for Date/Map/Set, which no caller snapshots.
+export function stateSnapshot<T>(state: T): T {
+	return $state.snapshot(state) as T
 }
 export function refreshStateStore<T>(store: StateStore<T>): void {
 	store.val = $state.snapshot(store.val) as any