Adds a compact `setup --status` view, a `setup --clean` for regenerable
session checkpoints, and `--tools`/`--plugins` scaffolding for
~/.deepseek/{tools,plugins} so the extension model has a documented home
that doctor can count. `doctor --json` lands as a CI-safe alternative to
the human-readable doctor (skips the live API probe).
Also locks down the engine's hostility to fake tool-call wrappers:
filter_tool_call_delta and the marker constants are now testable, the
streaming loop emits one compact status notice per turn when it strips
a wrapper, and a new protocol_recovery integration test asserts that
the legacy text parser never turns <function_calls> into a real tool
call. Adds 23 unit tests + 14 integration tests covering both slices.
Hunter Bown
853a39138c