Add root package.json for dependency management

[EricGrill]

Problem

Repository lacks a root package.json for dependency management and tooling.

Current state:

• No root package.json
• No centralized way to manage dev dependencies
• Scripts in scripts/ directory have no dependency management
• No npm scripts for common tasks
• No lockfile for reproducible builds

Why it matters:
Without a root package.json:

• Contributors can't easily run linting, formatting, or validation
• CI can't cache dependencies effectively
• No standardized way to add development tooling
• Harder to enforce code quality standards

Suggested Solution

Create a root package.json with:

{
  "name": "agents-skills-plugins",
  "version": "1.0.0",
  "description": "Claude Code Plugin Marketplace - Community plugins, agents, and skills",
  "private": true,
  "scripts": {
    "validate": "node scripts/validate-plugins.js",
    "lint": "eslint scripts/",
    "format": "prettier --write '**/*.json' '**/*.md'",
    "test": "npm run validate",
    "update-index": "node scripts/update-index.js"
  },
  "devDependencies": {
    "ajv-cli": "^5.0.0",
    "prettier": "^3.0.0",
    "eslint": "^8.0.0"
  }
}

Acceptance Criteria

• Root package.json created
• Dev dependencies for validation/linting
• npm scripts for common tasks
• CI updated to use npm scripts
• package-lock.json committed

[EricGrill]

Triage: Roadmap ✅

Decision: Add to Q2 roadmap.
Milestone: v1.0.0 — Repo Foundation
Priority: P1
Adding a root package.json with validation/lint scripts and dev dependencies is foundational for CI and contributor onboarding.