Introduce VERSION as the app version source of truth and add make bump-patch to increment VERSION, commit, and create a matching vX.Y.Z tag.
Wire VERSION into build outputs by injecting it into webterm.Version for make build-go and Docker image builds, and include VERSION in Docker build context.
Also remove the visible dashboard container count subtitle while keeping count updates in browser console logs.
Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>