Development record

The brief at .abcd/development/brief/04-surfaces/36-dashboard.md:96 says: Start refuses outside a checkout abcd manages, when a dashboard already runs, when Tailscale is not running or too old, when the tailscale command sits in the working tree or a world-writable folder, and when the port is Serve's or Funnel's; Stop (line 117) is described with no refusal at all. The shipped surface differs: `abcd dashboard stop --help` names its refusal as 'refuses when another start or stop holds the lock', and both start and stop take a file lock under ~/.abcd.noindex/dashboard/ with a 5s timeout (internal/surface/dashboard/control.go:41, :246, :642). The chapter never mentions the lock or the refusal it raises. (v0.14.2 release crosscheck, undocumented-surface, raised by opus in a27.)