v2.212.1 — the networked transport's generated bearer token no longer lands in server.log

Fixed

• A generated transport token was written to logs/server.log in cleartext (CWE-532).
  Starting --transport sse or --transport streamable-http without pinning
  $DAVINCI_MCP_TOKEN logged the fresh token verbatim. The transport logger
  has no handler of its own, so the record propagated to the root logger,
  which src/server.py points at logs/server.log — opened with the default
  file mode (0644 under the usual umask), appended to forever, and never
  cleared. That copy was strictly less protected and strictly more durable
  than the one the code deliberately locks down: the 0600 state file under
  the per-user private directory, deleted in run_networked's finally. The
  token is the transport's only access control, and the control panel's
  sibling token was already kept out of argv and logs against exactly this
  local-user threat. The log line now names the state file's path instead of
  the value, and a generated token is echoed only to an interactive stderr
  (a redirected stderr is another file). The state file remains the
  hand-back channel the control panel already reads. Reported privately by an
  external security researcher, with a reproduction against the real
  run_networked and the server's real root-logger configuration.

Documentation

• SECURITY.md now states the rule outright: the pidfile and the transport
  state file are the only on-disk copies of either token, and neither is
  written to logs/server.log. The mcp_transport module docstring no longer
  says the token is "logged at startup".

Validation

• A regression test runs the real run_networked (uvicorn stubbed) with a
  root FileHandler configured the way src/server.py configures it, and
  asserts the token is absent from the file, the state-file path is present,
  a redirected stderr never carries it, an interactive stderr carries it
  exactly once, and a pinned token is echoed nowhere. Against the previous
  code the test fails with the token found in the log — the reporter's
  finding, reproduced.