feat(filterManager): add debouced state support and move manager

src/features/GetFonts/lib/filterManager/filterManager.svelte.ts

@@ -0,0 +1,63 @@
+import { createFilter } from '$shared/lib';
+import { createDebouncedState } from '$shared/lib/helpers';
+import type { FilterConfig } from '../../model';
+
+/**
+ * Create a filter manager instance.
+ */
+export function createFilterManager<TValue extends string>(config: FilterConfig<TValue>) {
+    const search = createDebouncedState(config.queryValue ?? '');
+
+    // Create filter instances upfront
+    const groups = $state(
+        config.groups.map(config => ({
+            id: config.id,
+            label: config.label,
+            instance: createFilter({ properties: config.properties }),
+        })),
+    );
+
+    // Derived: any selection across all groups
+    const hasAnySelection = $derived(
+        groups.some(group => group.instance.selectedProperties.length > 0),
+    );
+
+    return {
+        // Getter for queryValue (immediate value for UI)
+        get queryValue() {
+            return search.immediate;
+        },
+
+        // Setter for queryValue
+        set queryValue(value) {
+            search.immediate = value;
+        },
+
+        // Getter for queryValue (debounced value for logic)
+        get debouncedQueryValue() {
+            return search.debounced;
+        },
+
+        // Direct array reference (reactive)
+        get groups() {
+            return groups;
+        },
+
+        // Derived values
+        get hasAnySelection() {
+            return hasAnySelection;
+        },
+
+        // Global action
+        deselectAllGlobal: () => {
+            groups.forEach(group => group.instance.deselectAll());
+        },
+
+        // Helper to get group by id
+        getGroup: (id: string) => {
+            return groups.find(g => g.id === id);
+        },
+    };
+}
+
+export type FilterManager = ReturnType<typeof createFilterManager>;