✅ chore: verify monorepo support implementation

[Copilot]

This PR documents verification that the monorepo support feature request is fully implemented and production-ready.

Verification Scope

All 5 requested input parameters implemented in action.yml:

• monorepo: Enable monorepo mode (default: false)
• package-paths: Manual package list specification
• workspace-detection: Auto-discover from root package.json workspaces
• changed-only: Event-aware git diff to build only changed packages
• dependency-order: Topological sort using Kahn's algorithm

Implementation Evidence

Core Scripts (2,696+ LOC total):

• monorepo-orchestrator.sh (586L): Main orchestration with per-package flow detection
• discover-workspaces.sh (348L): Workspace auto-discovery with glob pattern support
• detect-changed-packages.sh (284L): Event-aware change detection (PR/push/release)
• resolve-dependency-order.js (214L): Dependency-aware build ordering with circular dependency detection
• pr-comment.js (400L): Enhanced PR comments with package status table
• generate-outputs.sh (131L): Aggregated monorepo outputs

Key Features Verified:

• 100% backwards compatible (conditional if: inputs.monorepo == 'true' gates)
• Workspace discovery supports both array and object formats, filters private packages
• Change detection handles root config changes, shallow clones, and safe fallbacks
• Dependency ordering with O(n+e) performance, duplicate/circular detection
• Security audit per package, dry-run support, GitHub package scoping

Documentation:

• README with comprehensive monorepo section (25+ references)
• Example workflows: examples/monorepo-workflow.yml, examples/workspace-auto-discovery.yml
• All 9 monorepo-specific outputs documented

Usage Example

- uses: wgtechlabs/package-build-flow-action@v2
  with:
    monorepo: 'true'                    # Activates monorepo pipeline
    workspace-detection: 'true'         # Auto-discover from workspaces field
    changed-only: 'true'                # Build only changed packages
    dependency-order: 'true'            # Topological sort
    registry: 'both'
    npm-token: ${{ secrets.NPM_TOKEN }}

Design Principles Met

• Backwards compatible: existing users change nothing
• Opt-in: single monorepo: 'true' flag
• Phased delivery: incremental commits in git history
• Single-package scripts untouched

The feature is complete and ready for production use.

Original prompt

---

This section details on the original issue you should resolve

<issue_title>Monorepo Support</issue_title>
<issue_description>### Description

Add monorepo/workspace support to Package Build Flow Action, enabling users to build, version, and publish multiple packages from a single repository while maintaining full backwards compatibility with single-package mode.

Motivation

Currently the action operates on a single package.json. Many modern projects (like tinyclaw) use monorepo structures with workspaces containing multiple publishable packages (core libraries, plugins, CLIs). Users need the same intelligent flow detection, pre-release versioning, and publishing capabilities — but applied per-package across the monorepo.

This gives Package Build Flow a significant advantage over Changesets:

• ✅ Automatic SHA-based pre-releases for debugging (no manual changeset files)
• ✅ Dry-run mode built-in
• ✅ Security audit per package
• ✅ PR comments with ALL package install instructions
• ✅ Zero manual steps — fully git-event driven

Design Principles

1. 100% backwards compatible — monorepo defaults to false, existing users change nothing
2. Opt-in via single flag — monorepo: 'true' activates the new pipeline
3. Phased delivery — ship value incrementally across 5 phases
4. Existing scripts stay untouched for single-package mode — new scripts + conditional if: gates in action.yml

New Input Parameters

monorepo:
  description: 'Enable monorepo mode'
  default: 'false'

package-paths:
  description: 'Comma-separated list of package.json paths (Phase 1 manual mode)'
  default: ''

workspace-detection:
  description: 'Auto-detect workspaces from root package.json'
  default: 'true'

changed-only:
  description: 'Only build/publish packages that changed since last release'
  default: 'true'

dependency-order:
  description: 'Build packages in dependency order (topological sort)'
  default: 'true'
```</issue_description>

<agent_instructions>Verify if this feature request has been implemented.</agent_instructions>

## Comments on the Issue (you are @copilot in this section)

<comments>
</comments>

• Fixes Monorepo Support #13

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