feat(mapper): map package-less monorepo roots

[vincentkoc]

Summary

• map package-less Node/TypeScript app roots discovered from workspace patterns and conventional monorepo folders
• support hoisted Next route mapping for package-less app roots, including deep App Router and API-only routes
• pin oxfmt indentation config and add no-publish release-prep docs/checklist

Validation

• codex review --base origin/main: clean after fix loop
• pnpm -s format:check
• pnpm -s typecheck
• pnpm -s lint
• pnpm exec vitest run src/mapper.test.ts --maxWorkers=1
• pnpm -s test
• pnpm -s build
• pnpm -s pack:smoke
• npm pack --dry-run --json --ignore-scripts
• git diff --check

No release was performed; these changes will be added to the next release.