Add settings page for managing forecasting API key and URL via UI

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

frontend/node_modules/es-toolkit/dist/compat/string/startsWith.d.ts

@@ -0,0 +1,21 @@
+//#region src/compat/string/startsWith.d.ts
+/**
+ * Checks if a string contains another string at the beginning of the string.
+ *
+ * Checks if one string startsWith another string. Optional position parameter to start searching from a certain index.
+ *
+ * @param str - The string that might contain the target string.
+ * @param target - The string to search for.
+ * @param position - An optional offset to start searching in the str string
+ * @returns True if the str string starts with the target string.
+ *
+ * @example
+ * const isPrefix = startsWith('fooBar', 'foo') // returns true
+ * const isPrefix = startsWith('fooBar', 'bar') // returns false
+ * const isPrefix = startsWith('fooBar', 'abc') // returns false
+ * const isPrefix = startsWith('fooBar', 'Bar', 2) // returns true
+ * const isPrefix = startsWith('fooBar', 'Bar', 5) // returns false
+ */
+declare function startsWith(str?: string, target?: string, position?: number): boolean;
+//#endregion
+export { startsWith };