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/string/pad.d.mts

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+//#region src/string/pad.d.ts
+/**
+ * Pads string on the left and right sides if it's shorter than length. Padding characters are truncated if they can't be evenly divided by length.
+ * If the length is less than or equal to the original string's length, or if the padding character is an empty string, the original string is returned unchanged.
+ *
+ * @param str - The string to pad.
+ * @param [length] - The length of the resulting string once padded.
+ * @param [chars] - The character(s) to use for padding.
+ * @returns The padded string, or the original string if padding is not required.
+ *
+ * @example
+ * const result1 = pad('abc', 8);         // result will be '  abc   '
+ * const result2 = pad('abc', 8, '_-');   // result will be '_-abc_-_'
+ * const result3 = pad('abc', 3);         // result will be 'abc'
+ * const result4 = pad('abc', 2);         // result will be 'abc'
+ *
+ */
+declare function pad(str: string, length: number, chars?: string): string;
+//#endregion
+export { pad };