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/ajv/lib/vocabularies/jtd/optionalProperties.ts

@@ -0,0 +1,15 @@
+import type {CodeKeywordDefinition} from "../../types"
+import type {KeywordCxt} from "../../compile/validate"
+import {validateProperties, error} from "./properties"
+
+const def: CodeKeywordDefinition = {
+  keyword: "optionalProperties",
+  schemaType: "object",
+  error,
+  code(cxt: KeywordCxt) {
+    if (cxt.parentSchema.properties) return
+    validateProperties(cxt)
+  },
+}
+
+export default def