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/package.json

@@ -0,0 +1,29 @@
+{
+  "name": "@mosaic/prdy",
+  "version": "0.1.0",
+  "type": "module",
+  "description": "Mosaic PRD wizard — TypeScript rewrite",
+  "scripts": {
+    "build": "tsc -p tsconfig.json",
+    "typecheck": "tsc --noEmit",
+    "lint": "eslint src/",
+    "test": "vitest run"
+  },
+  "dependencies": {
+    "@mosaic/types": "workspace:*",
+    "@clack/prompts": "^0.9",
+    "commander": "^13",
+    "js-yaml": "^4",
+    "zod": "^3.24"
+  },
+  "devDependencies": {
+    "@types/node": "^22",
+    "@types/js-yaml": "^4",
+    "typescript": "^5",
+    "vitest": "^2"
+  },
+  "publishConfig": {
+    "registry": "https://git.mosaicstack.dev/api/packages/mosaic/npm",
+    "access": "public"
+  }
+}