refactor(GetFonts): centralize filterManager/sortStore → fontStore bridge

Move the duplicated $effect blocks that mapped filterManager and sortStore
into fontStore params out of Search, FontSearch and FilterControls into a
single $effect.root in features/GetFonts/model/state/bindings.svelte.ts.

Consumers now bind to the manager/store directly; the bridge is installed
once via a side-effect import from the feature barrel.

src/features/GetFonts/model/state/bindings.svelte.ts

@@ -0,0 +1,36 @@
+/**
+ * Bridges feature-level UI state (filterManager + sortStore) to the
+ * entity-level fontStore query params.
+ *
+ * Centralizing this here means consumers (Search, FontSearch,
+ * FilterControls, etc.) bind to the manager/store directly without
+ * each repeating the same mapping effect. The bridge is a singleton
+ * concern — it tracks singleton state and writes to a singleton query
+ * observer, so it lives at module scope, not in any individual widget.
+ */
+
+import { fontStore } from '$entities/Font';
+import { untrack } from 'svelte';
+import { mapManagerToParams } from '../../lib/mapper/mapManagerToParams';
+import { sortStore } from '../store/sortStore.svelte';
+import { filterManager } from './manager.svelte';
+
+$effect.root(() => {
+    /**
+     * Mirror filter selections + debounced search query into fontStore params.
+     * untrack the write so fontStore's internal $state reads don't feed back
+     * into this effect's dependency graph.
+     */
+    $effect(() => {
+        const params = mapManagerToParams(filterManager);
+        untrack(() => fontStore.setParams(params));
+    });
+
+    /**
+     * Mirror sort selection into fontStore.
+     */
+    $effect(() => {
+        const apiSort = sortStore.apiValue;
+        untrack(() => fontStore.setSort(apiSort));
+    });
+});