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/recharts/lib/util/getSliced.js

@@ -0,0 +1,15 @@
+"use strict";
+
+Object.defineProperty(exports, "__esModule", {
+  value: true
+});
+exports.getSliced = getSliced;
+function getSliced(arr, startIndex, endIndex) {
+  if (!Array.isArray(arr)) {
+    return arr;
+  }
+  if (arr && startIndex + endIndex !== 0) {
+    return arr.slice(startIndex, endIndex + 1);
+  }
+  return arr;
+}