fix(filters): use proxy fetch function

src/entities/Font/api/proxy/filters.ts

@@ -0,0 +1,83 @@
+/**
+ * Proxy API filters
+ *
+ * Fetches filter metadata from GlyphDiff proxy API.
+ * Provides type-safe response handling.
+ *
+ * @see https://api.glyphdiff.com/api/v1/filters
+ */
+
+import { api } from '$shared/api/api';
+
+/**
+ * Filter metadata type from backend
+ */
+export interface FilterMetadata {
+    /** Filter ID (e.g., "providers", "categories", "subsets") */
+    id: string;
+
+    /** Display name (e.g., "Font Providers", "Categories", "Character Subsets") */
+    name: string;
+
+    /** Filter description */
+    description: string;
+
+    /** Filter type */
+    type: 'enum' | 'string' | 'array';
+
+    /** Available filter options */
+    options: FilterOption[];
+}
+
+/**
+ * Filter option type
+ */
+export interface FilterOption {
+    /** Option ID (e.g., "google", "serif", "latin") */
+    id: string;
+
+    /** Display name (e.g., "Google Fonts", "Serif", "Latin") */
+    name: string;
+
+    /** Option value (e.g., "google", "serif", "latin") */
+    value: string;
+
+    /** Number of fonts with this value */
+    count: number;
+}
+
+/**
+ * Proxy filters API response
+ */
+export interface ProxyFiltersResponse {
+    /** Array of filter metadata */
+    filters: FilterMetadata[];
+}
+
+/**
+ * Fetch filters from proxy API
+ *
+ * @returns Promise resolving to array of filter metadata
+ * @throws ApiError when request fails
+ *
+ * @example
+ * ```ts
+ * // Fetch all filters
+ * const filters = await fetchProxyFilters();
+ *
+ * console.log(filters); // [
+ * //   { id: "providers", name: "Font Providers", options: [...] },
+ * //   { id: "categories", name: "Categories", options: [...] },
+ * //   { id: "subsets", name: "Character Subsets", options: [...] }
+ * // ]
+ * ```
+ */
+export async function fetchProxyFilters(): Promise<FilterMetadata[]> {
+    const response = await api.get<FilterMetadata[]>('/api/v1/filters');
+
+    if (!response.data || !Array.isArray(response.data)) {
+        throw new Error('Proxy API returned invalid response');
+    }
+
+    return response.data;
+}