feat(quality-rails): migrate @mosaic/quality-rails from v0 to v1

Implements the full quality-rails scaffolding package in v1:
- types.ts: ProjectKind, QualityProfile, RailsConfig, ScaffoldResult
- detect.ts: project kind detection (node/python/rust/unknown)
- templates.ts: ESLint, Biome, pyproject, rustfmt, pre-commit, PR checklist templates
- scaffolder.ts: core scaffolding engine with file writing and dependency installation
- cli.ts: Commander.js CLI with init/check/doctor subcommands
- index.ts: re-exports all public API
- package.json: adds commander dep, type=module, @types/node devDep

All three quality gates pass (format:check, typecheck, lint).

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

packages/quality-rails/package.json

@@ -1,6 +1,7 @@
 {
   "name": "@mosaic/quality-rails",
   "version": "0.0.0",
+  "type": "module",
   "main": "dist/index.js",
   "types": "dist/index.d.ts",
   "exports": {
@@ -15,7 +16,11 @@
     "typecheck": "tsc --noEmit",
     "test": "vitest run --passWithNoTests"
   },
+  "dependencies": {
+    "commander": "^12.0.0"
+  },
   "devDependencies": {
+    "@types/node": "^22.0.0",
     "typescript": "^5.8.0",
     "vitest": "^2.0.0"
   }