feat: add FontFetchError and FontParseError typed errors

src/entities/Font/model/store/appliedFontsStore/errors.ts

@@ -0,0 +1,35 @@
+/**
+ * Thrown when a font file cannot be retrieved from the network or cache.
+ *
+ * @property url - The URL that was requested.
+ * @property cause - The underlying error, if any.
+ * @property status - HTTP status code. Present on HTTP errors, absent on network failures.
+ */
+export class FontFetchError extends Error {
+    readonly name = 'FontFetchError';
+
+    constructor(
+        public readonly url: string,
+        public readonly cause?: unknown,
+        public readonly status?: number,
+    ) {
+        super(status ? `HTTP ${status} fetching font: ${url}` : `Network error fetching font: ${url}`);
+    }
+}
+
+/**
+ * Thrown by {@link loadFont} when a font buffer cannot be parsed into a {@link FontFace}.
+ *
+ * @property fontName - The display name of the font that failed to parse.
+ * @property cause - The underlying error from the FontFace API.
+ */
+export class FontParseError extends Error {
+    readonly name = 'FontParseError';
+
+    constructor(
+        public readonly fontName: string,
+        public readonly cause?: unknown,
+    ) {
+        super(`Failed to parse font: ${fontName}`);
+    }
+}