v0.1.3

Adds a built-in tool, so the server is never an empty one.

dvera_check_environment is answered by the server itself, with no CT installation behind it. It reports whether a local CT install is usable by DVERA and what to do when it is not: no install found, an install too old to ship the MCP bundle, a CT_HOME pointing at a directory that does not exist, an unreadable tool catalog, or an install that appeared after the MCP client started and needs a restart to be picked up.

A machine without CT therefore lists one tool rather than none. Where CT is installed, the 21 verification tools are unchanged and the new one joins them.

Also in this release: the initialize instructions no longer say CT is absent when it is installed but unusable, and a cancellation notification is now applied only to a request that is still outstanding.