chore: untrack boost-generated AI artifacts

[gvieira18]

Why

boost.json, .mcp.json, CLAUDE.md, and the .claude/ skills are all generated and re-updated automatically every time someone runs php artisan boost:install or boost:update. Versioning them produces noisy diffs and churn on files nobody edits by hand.

This PR stops tracking them so they stay purely local, matching the AI-artifacts convention already used in he4rt/heartdevs.com. It also moves laravel/boost itself to require-dev, since it is a dev-only tool.

What changed

• Added an # === AI Agents === section to .gitignore covering every path a Laravel Boost agent writes — audited directly against laravel/boost v2.7.0 (src/Install/Agents/*.php), all 13 agents:
  • Guidelines: CLAUDE.md, AGENTS.md, .github/copilot-instructions.md
  • MCP config: .mcp.json, .codex/, .cursor/, .amp/, .pi/, .junie/, .grok/, .factory/, .agents/, .kiro/, opencode.json(c) (.vscode/, .zed/ already ignored at root)
  • Skills: .claude/skills, .ai/, .agents/skills, .kiro/skills
  • Plus boost.json
• Untracked the previously committed artifacts with git rm --cached (files remain on disk):
  • boost.json, .mcp.json, CLAUDE.md, .claude/skills/**
• Dropped the now-redundant .claude/settings.local.json line, superseded by the broader .claude/ rule.
• Moved laravel/boost from require to require-dev in composer.json, so it is excluded from production installs (composer install --no-dev). The ^2.0 constraint and the locked v2.7.0 are preserved — no version bump.

Not in scope

• laravel/boost stays a dependency (dev) — the tool keeps regenerating these files locally.
• No He4rtBoostReminder command copied over.

Verification

• git check-ignore -v confirms all 14 AI target paths are ignored.
• Files still present on disk after git rm --cached.
• php artisan boost:install re-run produces zero tracked changes — every regenerated artifact lands on an ignored path.
• No committed provider references laravel/boost, so dropping it from production installs is safe.