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/theme/graphicalItemIdentity.js

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+"use strict";
+
+Object.defineProperty(exports, "__esModule", {
+  value: true
+});
+exports.graphicalItemIdentity = graphicalItemIdentity;
+/**
+ * @fileOverview
+ * This file provides helper methods for assigning theme identity to a
+ * graphical item. Graphical items are individual drawable data representations,
+ * such as Line or Bar. In previous Recharts versions these can be styled
+ * individually. In next version, Recharts will allow the user to provide an
+ * array of themes, and then have the graphical items pick one. There is a gap
+ * however; graphical items are not sorted and not indexed. We can't use DOM
+ * order because that order changes. So instead we need an identifier that:
+ * - we can calculate from props, without requiring the user to provide an
+ *   explicit id
+ * - is stable across renders, so that the same item will always get the same
+ *   theme
+ * - is (within possibilities) unique across all items, so that no two items
+ *   will get the same theme The uniqueness is impossible to guarantee 100% so
+ * we will only provide a best-effort. This file provides a helper method to
+ * calculate such an identifier.
+ */
+
+/**
+ * Computes a deterministic numeric hash for the given string. Uses djb2 hash
+ * algorithm with additional bit-mixing to improve distribution across small
+ * moduli (e.g., themeCount = 5).
+ */
+function computeHash(str) {
+  var hash = 5381;
+  for (var i = 0; i < str.length; i++) {
+    hash = (hash << 5) + hash + str.charCodeAt(i); // hash * 33 + charCode
+  }
+
+  // Bit-mixing step: multiply by a large prime, then XOR-shift to spread
+  // bit patterns. This prevents collisions that can occur with raw %
+  // themeCount when the raw hash's low bits correlate poorly across inputs.
+  hash ^= hash >>> 16;
+  hash *= 0x85ebca6b;
+  hash ^= hash >>> 16;
+  return hash & 0x7fffffff; // Mask to ensure non-negative 31-bit integer
+}
+
+/**
+ * Calculates theme index from a given item. The identity is computed
+ * deterministically from the dataKey string, ensuring stability across renders
+ * and module reloads.
+ * @param item - The themable item to calculate identity for
+ * @param themeCount - Optional number of available themes; if provided, clamps
+ *  the hash to [0, themeCount).
+ */
+function graphicalItemIdentity(item, themeCount) {
+  // Negative or zero themeCount is semantically invalid (can't have negative themes,
+  // and zero themes means none available)
+  if (themeCount != null && themeCount <= 0) {
+    return 0;
+  }
+  var keyString = String(item.dataKey);
+  var hashResult = computeHash(keyString);
+  if (themeCount != null && themeCount > 0) {
+    return hashResult % themeCount;
+  }
+  return hashResult;
+}