chore(release): npm publish prep + version bump to 1.0.0 GA

[wesleysimplicio]

Context

package.json is at 0.1.0 with bin: marketing-engine already declared but the package has never been published. README.md § Quick start instructs npx marketing-engine init which fails today because nothing is on npm.

Goal

First-publishable artifact on npm with a clean smoke test.

Acceptance criteria

• All Sprint 1-5 features merged (gating prerequisite)
• package.json version bumped to 1.0.0 (semver: 0.x → 1.0 communicates "GA, no more scaffolding-only releases")
• package.json files array verified — must include bin/, lib/, .skills/, .specs/, .ralph/, .env.example, AGENTS.md, README.md, LICENSE, playwright.config.ts, tsconfig.json (already declared; verify)
• Smoke test: npm pack && npm install --global ./marketing-engine-1.0.0.tgz && marketing-engine help exits 0
• CI workflow .github/workflows/release.yml (new) publishes on tag v1.* push using NPM_TOKEN secret
• CHANGELOG.md entry [1.0.0] - <date> summarizing what shipped
• README badges (CI, npm version, npm downloads) added
• Verify npx marketing-engine@1.0.0 init works end-to-end in a fresh tmp dir

Files

• package.json
• New: .github/workflows/release.yml
• README.md, CHANGELOG.md

[wesleysimplicio]

Closed after PR #40 follow-up stabilization in commit f40b58d. Current main passes npm run typecheck and npm run test:e2e (119 Playwright specs green), and this tracker item is being retired per repository cleanup.