feat(wave3): add @mosaic/prdy — TypeScript PRD wizard

- PRD CRUD: createPrd, loadPrd, savePrd, listPrds
- Interactive wizard using @clack/prompts
- Built-in templates: software, feature, spike
- CLI: prdy init | list | show
- Depends on @mosaic/types workspace:*

packages/prdy/tests/prd.test.ts

@@ -0,0 +1,36 @@
+import { promises as fs } from 'node:fs';
+import os from 'node:os';
+import path from 'node:path';
+
+import { describe, expect, it } from 'vitest';
+
+import { createPrd, listPrds, loadPrd } from '../src/prd.js';
+
+describe('prd document lifecycle', () => {
+  it('creates and loads PRD documents', async () => {
+    const projectDir = await fs.mkdtemp(path.join(os.tmpdir(), 'prdy-project-'));
+
+    try {
+      const created = await createPrd({
+        name: 'User Authentication',
+        projectPath: projectDir,
+        template: 'feature',
+      });
+
+      expect(created.title).toBe('User Authentication');
+      expect(created.status).toBe('draft');
+      expect(created.id).toMatch(/^user-authentication-\d{8}-\d{6}$/);
+
+      const loaded = await loadPrd(projectDir);
+      expect(loaded.id).toBe(created.id);
+      expect(loaded.title).toBe(created.title);
+      expect(loaded.sections.length).toBeGreaterThan(0);
+
+      const listed = await listPrds(projectDir);
+      expect(listed).toHaveLength(1);
+      expect(listed[0]?.id).toBe(created.id);
+    } finally {
+      await fs.rm(projectDir, { recursive: true, force: true });
+    }
+  });
+});

packages/prdy/tests/templates.test.ts

@@ -0,0 +1,22 @@
+import { describe, expect, it } from 'vitest';
+
+import { BUILTIN_PRD_TEMPLATES } from '../src/templates.js';
+
+describe('built-in PRD templates', () => {
+  it('includes software, feature, and spike templates with required fields', () => {
+    expect(BUILTIN_PRD_TEMPLATES.software).toBeDefined();
+    expect(BUILTIN_PRD_TEMPLATES.feature).toBeDefined();
+    expect(BUILTIN_PRD_TEMPLATES.spike).toBeDefined();
+
+    for (const template of Object.values(BUILTIN_PRD_TEMPLATES)) {
+      expect(template.sections.length).toBeGreaterThan(0);
+      expect(template.fields.length).toBeGreaterThan(0);
+
+      for (const section of template.sections) {
+        expect(section.id.length).toBeGreaterThan(0);
+        expect(section.title.length).toBeGreaterThan(0);
+        expect(section.fields.length).toBeGreaterThan(0);
+      }
+    }
+  });
+});