"What is running where" was answerable only by asking someone. Each tool
now reports its own version on startup into a ToolVersion registry, shown
on Pipeline → Machines.
The worker's version moves out of config.json and into the assembly:
a hand-maintained string on each machine is exactly the thing that goes
stale, and a machine reporting a version it is not running is worse than
no version at all. publish.ps1 stamps the git SHA via SourceRevisionId,
so a deployed exe traces back to a commit (1.1.0+feb1c7b).
The panel gains PANEL_VERSION, shown in its title and every diagnostics
report, and pings on load.
Staleness is derived rather than declared: the newest version seen for a
tool is the benchmark, so updating one machine is what flags the rest.
There is no expected-version list to keep in sync — which would have been
one more thing to forget.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>