Issue Description

Implement a collection-based plugin distribution system replacing the previously planned persona-based approach. Collections are domain-focused artifact groupings defined as YAML manifests, with automated plugin generation, schema validation, and marketplace registry support.

This issue documents the implementation delivered in PR #439 and supersedes Phases 1, 2, 3, 6, and 8 of the original persona distribution epic (#431). Phase 1b and Phase 7 goals are achieved within this work. Phases 4 and 5 retain partial relevance and are tracked separately.

Motivation

The original persona-based approach used a central JSON registry (ai-artifacts-registry.json) with role-based persona tags (developer, tpm, devops, architect, technical-writer) to filter artifacts. This was replaced by a simpler architecture where:

• Domain-focused collections directly list their items by path and kind in YAML manifests
• No central registry is needed — each collection is self-contained
• Plugin generation is fully automated from manifests via Generate-Plugins.ps1
• 10 domain collections replace 5 role-based personas, offering more composable and intuitive groupings

Key Architectural Decisions

Deliverables

1. Collection Manifest System

• 10 collection manifests in collections/*.collection.yml with companion .collection.md descriptions
• Schema at scripts/linting/schemas/collection-manifest.schema.json with required fields (id, name, description, items) and optional fields (tags, display, maturity per item)
• Item kinds: agent, prompt, instruction, skill, hook

Collections:

2. Plugin Generation Pipeline

• scripts/plugins/Generate-Plugins.ps1 — generates Copilot CLI plugin directories from collection manifests with symlinks, plugin.json manifests, and auto-generated READMEs
• scripts/plugins/Modules/PluginHelpers.psm1 — shared pure functions for manifest parsing and frontmatter extraction
• Generated output under plugins/ (gitignored) with one subdirectory per collection
• hve-core-all auto-discovers all non-deprecated artifacts

3. Collection Validation

• scripts/plugins/Validate-Collections.ps1 — validates all collection manifests for structure, required fields, artifact path existence, kind-suffix consistency, and duplicate ID detection
• npm run plugin:validate / npm run lint:collections-metadata for CI integration

4. Marketplace Registry

• .github/plugin/marketplace.json — centralized registry of all generated plugins with name, version, source path, and description
• Auto-updated during plugin generation

5. Extension Packaging Updates

• Prepare-Extension.ps1 updated to load collection manifests, filter by maturity and collection membership, resolve transitive handoff dependencies, and generate package.json contributes
• Package-Extension.ps1 updated for collection-aware artifact copying
• Collection-level maturity gating: experimental collections build only for PreRelease channel, deprecated collections excluded entirely

6. Maturity Migration (from Phase 1b)

• maturity field removed from all artifact frontmatter files and schemas
• Maturity tracked as optional per-item field in collection manifests
• Resolves Copilot CLI incompatibility (#360)

7. Documentation Updates (partial, from Phase 4)

• Architecture docs updated for collection model
• Contributing guides updated for collection authoring
• extension/PACKAGING.md documents the full pipeline
• Getting started docs reflect collection-based installation

Breaking Changes

• maturity frontmatter field removed from all 61+ artifact files
• Frontmatter schemas updated to remove maturity property
• extension/package.json contributes section generated at build time (no longer static)
• Extension packaging scripts have new parameters (-Collection, collection-aware filtering)
• ai-artifacts-registry.json removed (previously proposed in Phase 1)
• Validate-ArtifactRegistry.ps1 removed (replaced by Validate-Collections.ps1)

NPM Scripts

Superseded Issues

This implementation supersedes the following issues from the persona distribution epic:

Remaining Work (Separate Issues)

Acceptance Criteria

• 10 domain-focused collection manifests defined in collections/*.collection.yml
• Collection manifest schema validates all manifests
• Plugin generation produces symlink-based plugins under plugins/
• hve-core-all auto-discovers all non-deprecated artifacts
• Collection validation catches missing files, invalid kinds, and duplicate IDs
• Marketplace registry lists all generated plugins
• Extension packaging respects collection-level maturity gating
• Maturity removed from all artifact frontmatter
• Handoff dependencies resolved transitively from agent frontmatter
• Architecture and contributing documentation updated for collection model
• PACKAGING.md documents the full plugin generation and extension packaging pipeline

Related Issues

• Epic: #431 — Persona-Based Extension Distribution
• Copilot CLI fix: #360 — Custom maturity frontmatter breaks Copilot CLI
• Skill distribution: #251 — Update extension packaging to distribute skills