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/array/flatten.js

@@ -0,0 +1,19 @@
+const require_isArrayLike = require("../predicate/isArrayLike.js");
+//#region src/compat/array/flatten.ts
+function flatten(value, depth = 1) {
+	const result = [];
+	const flooredDepth = Math.floor(depth);
+	if (!require_isArrayLike.isArrayLike(value)) return result;
+	const recursive = (arr, currentDepth) => {
+		for (let i = 0; i < arr.length; i++) {
+			const item = arr[i];
+			if (currentDepth < flooredDepth && (Array.isArray(item) || Boolean(item?.[Symbol.isConcatSpreadable]) || item !== null && typeof item === "object" && Object.prototype.toString.call(item) === "[object Arguments]")) if (Array.isArray(item)) recursive(item, currentDepth + 1);
+			else recursive(Array.from(item), currentDepth + 1);
+			else result.push(item);
+		}
+	};
+	recursive(Array.from(value), 0);
+	return result;
+}
+//#endregion
+exports.flatten = flatten;