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/es6/state/reduxDevtoolsJsonStringifyReplacer.js

@@ -0,0 +1,12 @@
+export function reduxDevtoolsJsonStringifyReplacer(key, value) {
+  if (value instanceof HTMLElement) {
+    return "HTMLElement <".concat(value.tagName, " class=\"").concat(value.className, "\">");
+  }
+  if (value === window) {
+    return 'global.window';
+  }
+  if (key === 'children' && typeof value === 'object' && value !== null) {
+    return '<<CHILDREN>>';
+  }
+  return value;
+}