v0.16.1 — getting-started refresh

Patch release for PR #49 and the onboarding banner version fix.

Changed

• Refreshes docs/getting-started.md to separate Homebrew, source checkout, and PowerShell install flows.
• Documents the current management verbs for Homebrew and source-checkout users.

Fixed

• Onboarding banner now derives its displayed version from harness_manager.version instead of stale text.