feat(reader): STATUS.md parser + TS project scaffold [skip-tdd: visual for configs]

- vitest+TS scaffold (package.json/tsconfig/vitest.config = config artifacts)
- src/parser.ts: parses STATUS.md blocks → StatusBlock[]
- tests/parser.test.ts: 6 cases (single, multi, blocker, null-blocker, empty, unknown emoji)
- fix emoji contract: align with using-tasks reality (⚪ open / 🔴 in_progress / 🟡 paused / 🔵 blocked / 🟢 done); reader-task acceptance + design doc updated

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

vitest.config.ts

@@ -0,0 +1,8 @@
+import { defineConfig } from 'vitest/config';
+
+export default defineConfig({
+  test: {
+    include: ['tests/**/*.test.ts'],
+    globals: false,
+  },
+});