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/brushSlice.js

@@ -0,0 +1,34 @@
+import { createSlice } from '@reduxjs/toolkit';
+
+/**
+ * From all Brush properties, only height has a default value and will always be defined.
+ * Other properties are nullable and will be computed from offsets and margins if they are not set.
+ */
+
+var initialState = {
+  x: 0,
+  y: 0,
+  width: 0,
+  height: 0,
+  padding: {
+    top: 0,
+    right: 0,
+    bottom: 0,
+    left: 0
+  }
+};
+export var brushSlice = createSlice({
+  name: 'brush',
+  initialState,
+  reducers: {
+    setBrushSettings(_state, action) {
+      if (action.payload == null) {
+        return initialState;
+      }
+      return action.payload;
+    }
+  }
+});
+var setBrushSettings = brushSlice.actions.setBrushSettings;
+export { setBrushSettings };
+export var brushReducer = brushSlice.reducer;