AgentBar 1.6.0 — built-in updates

AgentBar now updates itself:

• quiet daily check of GitHub Releases
• Check for Updates… in the menu any time (current version shown as the row badge)
• one click on Update to X — Install & Relaunch: downloads, verifies the bundle, swaps the app in place (auto-rollback on failure), relaunches

Also fixes ragged menu indentation in the bottom section on macOS 26.

Users on 1.5.0 and older don't have the updater yet — update once via:

curl -fsSL https://raw.githubusercontent.com/michalstrnadel/AgentBar/main/Scripts/install.sh | bash
# or
brew upgrade --cask michalstrnadel/tap/agentbar

From 1.6.0 on, the app offers updates itself.