feat(mystery): parseEnding — markdown to typed Ending

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

src/world/loader.test.ts

@@ -1,5 +1,5 @@
 import { describe, it, expect } from 'vitest'
-import { parseRoom, parseItem } from './loader'
+import { parseRoom, parseItem, parseEnding } from './loader'
 
 const FOYER_MD = `---
 id: foyer
@@ -214,3 +214,35 @@ takeable: false
     expect(() => parseItem(md, 'items/x.md')).toThrow(/empty long description/i)
   })
 })
+
+const TRUE_ENDING_MD = `---
+id: true
+whenFlags:
+  ratGone: true
+---
+
+You stand at the top of the stair. The thing below has settled.
+
+The door behind you opens, and outside, finally, is morning.
+`
+
+describe('parseEnding', () => {
+  it('parses an ending with flags and prose', () => {
+    const result = parseEnding(TRUE_ENDING_MD, 'endings/true.md')
+    expect(result.id).toBe('true')
+    expect(result.ending.whenFlags).toEqual({ ratGone: true })
+    expect(result.ending.narration).toBe(
+      'You stand at the top of the stair. The thing below has settled.\n\nThe door behind you opens, and outside, finally, is morning.',
+    )
+  })
+
+  it('accepts an empty body (unreachable ending stub)', () => {
+    const md = `---
+id: wrong
+whenFlags: {}
+---
+`
+    const result = parseEnding(md, 'endings/wrong.md')
+    expect(result.ending.narration).toBe('')
+  })
+})

src/world/loader.ts

@@ -1,7 +1,7 @@
 import matter from 'gray-matter'
 import type { Room, RoomDescriptions, Item } from './types'
 import type { Direction } from '../engine/types'
-import { roomFrontmatterSchema, itemFrontmatterSchema } from './schema'
+import { roomFrontmatterSchema, itemFrontmatterSchema, endingFrontmatterSchema } from './schema'
 
 const WIKILINK = /^\[\[([^\]|]+)(?:\|[^\]]*)?\]\]$/
 
@@ -115,3 +115,19 @@ export function parseItem(raw: string, sourcePath: string): Item {
     takeable: fm.takeable,
   }
 }
+
+export interface ParsedEnding {
+  id: 'true' | 'wrong' | 'bad'
+  ending: { whenFlags: Record<string, string | boolean | number>; narration: string }
+}
+
+export function parseEnding(raw: string, _sourcePath: string): ParsedEnding {
+  const parsed = matter(raw)
+  // YAML parses bare `true` as boolean; coerce id to string before schema validation.
+  const data = { ...parsed.data, id: String(parsed.data.id) }
+  const fm = endingFrontmatterSchema.parse(data)
+  return {
+    id: fm.id,
+    ending: { whenFlags: fm.whenFlags, narration: parsed.content.trim() },
+  }
+}