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/chartDataSlice.js

@@ -0,0 +1,65 @@
+import { createSlice } from '@reduxjs/toolkit';
+import { castDraft } from 'immer';
+
+/**
+ * This is the data that's coming through main chart `data` prop
+ * Recharts is very flexible in what it accepts so the type is very flexible too.
+ * This will typically be an object, and various components will provide various `dataKey`
+ * that dictates how to pull data from that object.
+ *
+ * TL;DR: before dataKey
+ *
+ * @inline
+ */
+
+/**
+ * So this is the same unknown type as ChartData but this is after the dataKey has been applied.
+ * We still don't know what the type is - that depends on what exactly it was before the dataKey application,
+ * and the dataKey can return whatever anyway - but let's keep it separate as a form of documentation.
+ *
+ * TL;DR: ChartData after dataKey.
+ */
+
+export var initialChartDataState = {
+  chartData: undefined,
+  computedData: undefined,
+  dataStartIndex: 0,
+  dataEndIndex: 0
+};
+var chartDataSlice = createSlice({
+  name: 'chartData',
+  initialState: initialChartDataState,
+  reducers: {
+    setChartData(state, action) {
+      state.chartData = castDraft(action.payload);
+      if (action.payload == null) {
+        state.dataStartIndex = 0;
+        state.dataEndIndex = 0;
+        return;
+      }
+      if (action.payload.length > 0 && state.dataEndIndex !== action.payload.length - 1) {
+        state.dataEndIndex = action.payload.length - 1;
+      }
+    },
+    setComputedData(state, action) {
+      state.computedData = action.payload;
+    },
+    setDataStartEndIndexes(state, action) {
+      var _action$payload = action.payload,
+        startIndex = _action$payload.startIndex,
+        endIndex = _action$payload.endIndex;
+      if (startIndex != null) {
+        state.dataStartIndex = startIndex;
+      }
+      if (endIndex != null) {
+        state.dataEndIndex = endIndex;
+      }
+    }
+  }
+});
+var _chartDataSlice$actio = chartDataSlice.actions,
+  setChartData = _chartDataSlice$actio.setChartData,
+  setDataStartEndIndexes = _chartDataSlice$actio.setDataStartEndIndexes,
+  setComputedData = _chartDataSlice$actio.setComputedData;
+export { setChartData, setDataStartEndIndexes, setComputedData };
+export var chartDataReducer = chartDataSlice.reducer;