feat(prdy): migrate @mosaic/prdy from v0 to v1

Port full PRD wizard implementation: types, YAML persistence (js-yaml),
built-in templates (software/feature/spike), @clack/prompts interactive
wizard, and Commander.js CLI (init/list/show). Adapted for v1 conventions:
ESM .js imports, NodeNext resolution, noUncheckedIndexedAccess-safe lookups,
and consistent-type-imports lint rule.

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

packages/prdy/package.json

@@ -15,7 +15,15 @@
     "typecheck": "tsc --noEmit",
     "test": "vitest run --passWithNoTests"
   },
+  "dependencies": {
+    "@clack/prompts": "^0.9.0",
+    "commander": "^12.0.0",
+    "js-yaml": "^4.1.0",
+    "zod": "^3.22.0"
+  },
   "devDependencies": {
+    "@types/js-yaml": "^4.0.9",
+    "@types/node": "^22.0.0",
     "typescript": "^5.8.0",
     "vitest": "^2.0.0"
   }