feat(content): add Zod story graph schema and validation

src/content/__tests__/storySchema.test.ts

@@ -0,0 +1,79 @@
+import { describe, expect, it } from 'vitest';
+import { buildStoryContent } from '../storySchema';
+
+const resourcesById = {
+  supplies: { id: 'supplies', name: 'Supplies', startAmount: 0 },
+  coin: { id: 'coin', name: 'Coin', startAmount: 0 },
+};
+const actionsById = {
+  scout_path: { id: 'scout_path', name: 'Scout', durationMs: 1000, costs: [], yields: [{ resourceId: 'coin', amount: 1 }] },
+};
+
+const validNodes = [
+  {
+    id: 'boot_intro',
+    prose: 'You wake at the crossroads.',
+    triggers: [{ type: 'boot', targetNodeId: 'boot_intro' }],
+  },
+  {
+    id: 'fork_choice',
+    prose: 'Which way?',
+    choices: [
+      {
+        id: 'pick_a',
+        label: 'High road',
+        outcomes: [{ type: 'setFlag', flag: 'route_a' }],
+        targetNodeId: 'route_a_beat',
+      },
+      {
+        id: 'pick_b',
+        label: 'Low road',
+        outcomes: [{ type: 'setFlag', flag: 'route_b' }],
+        targetNodeId: 'route_b_beat',
+      },
+    ],
+  },
+  { id: 'route_a_beat', prose: 'The high road.' },
+  { id: 'route_b_beat', prose: 'The low road.' },
+];
+
+describe('buildStoryContent()', () => {
+  it('indexes nodes and finds boot trigger', () => {
+    const story = buildStoryContent(validNodes, actionsById, resourcesById);
+    expect(story.storyNodesById.fork_choice.prose).toContain('Which way');
+    expect(story.bootTargetNodeId).toBe('boot_intro');
+  });
+
+  it('rejects dangling targetNodeId on choices', () => {
+    expect(() =>
+      buildStoryContent(
+        [{ id: 'n', prose: 'x', choices: [{ id: 'c', label: 'y', outcomes: [], targetNodeId: 'missing' }] }],
+        actionsById,
+        resourcesById,
+      ),
+    ).toThrow(/unknown story node/i);
+  });
+
+  it('rejects unknown actionId in actionComplete trigger', () => {
+    expect(() =>
+      buildStoryContent(
+        [
+          {
+            id: 't',
+            prose: 'x',
+            triggers: [{ type: 'actionComplete', actionId: 'ghost', targetNodeId: 'boot_intro' }],
+          },
+          { id: 'boot_intro', prose: 'hi' },
+        ],
+        actionsById,
+        resourcesById,
+      ),
+    ).toThrow(/unknown action/i);
+  });
+
+  it('requires exactly one boot trigger', () => {
+    expect(() =>
+      buildStoryContent([{ id: 'n', prose: 'no boot' }], actionsById, resourcesById),
+    ).toThrow(/boot trigger/i);
+  });
+});