docs: clarify Hub free tier and hosted pricing ($7/mo)

[Tam-Leal]

Summary

• Landing Hub section: self-host first, then optional hosted pricing (free 1 machine / Pro $7/mo).
• Hub Create account: free for 1 machine; self-host for unlimited.
• Align published price to $7/month in Hub Settings button, main README, and hub README.

Type of change

• Bug fix (user-visible)
• Feature (user-visible)
• Documentation / site only
• Tests, CI, or refactor (no user-visible change)

Checklist

• I ran npm test locally (required for code changes)
• I smoke-tested with npm start if dashboard.html or API behavior changed
• No secrets in commits (config.json tokens, .env, PATs)
• Updated CHANGELOG.md under Unreleased when the change is notable

Release

• No GitHub Release needed (copy only; redeploy site + Hub after merge)
• Release needed

Test plan

• Landing #hub shows Pro ($7/mo); no em-dash
• Hub Create account mentions free 1 machine; Sign in unchanged
• Hub Settings shows Upgrade to Pro ($7/month)
• After merge: update Lemon Squeezy product price to $7 if still at $5; redeploy site + Hub

Made with Cursor