feat: bootstrap walking skeleton

src/content/schema.ts

@@ -0,0 +1,66 @@
+import { z } from 'zod';
+
+/**
+ * Content schemas.
+ *
+ * Game content (resources, actions, later story nodes) is data, validated at
+ * load time with zod so a malformed definition fails loudly instead of corrupting
+ * runtime state. The engine consumes the validated `Content` object and never
+ * reaches for raw definitions.
+ */
+
+export const resourceDefSchema = z.object({
+  id: z.string().min(1),
+  name: z.string().min(1),
+  startAmount: z.number().nonnegative().default(0),
+});
+
+export const actionDefSchema = z.object({
+  id: z.string().min(1),
+  name: z.string().min(1),
+  durationMs: z.number().positive(),
+  yields: z.object({
+    resourceId: z.string().min(1),
+    amount: z.number().positive(),
+  }),
+});
+
+export type ResourceDef = z.infer<typeof resourceDefSchema>;
+export type ActionDef = z.infer<typeof actionDefSchema>;
+
+export interface Content {
+  resources: ResourceDef[];
+  actions: ActionDef[];
+  resourcesById: Record<string, ResourceDef>;
+  actionsById: Record<string, ActionDef>;
+}
+
+function indexById<T extends { id: string }>(items: T[], kind: string): Record<string, T> {
+  const byId: Record<string, T> = {};
+  for (const item of items) {
+    if (byId[item.id]) {
+      throw new Error(`Duplicate ${kind} id "${item.id}"`);
+    }
+    byId[item.id] = item;
+  }
+  return byId;
+}
+
+/** Validate raw definitions and build the indexed, referentially-checked Content. */
+export function buildContent(input: { resources: unknown[]; actions: unknown[] }): Content {
+  const resources = input.resources.map((r) => resourceDefSchema.parse(r));
+  const actions = input.actions.map((a) => actionDefSchema.parse(a));
+
+  const resourcesById = indexById(resources, 'resource');
+  const actionsById = indexById(actions, 'action');
+
+  for (const action of actions) {
+    if (!resourcesById[action.yields.resourceId]) {
+      throw new Error(
+        `Action "${action.id}" yields unknown resource "${action.yields.resourceId}"`,
+      );
+    }
+  }
+
+  return { resources, actions, resourcesById, actionsById };
+}