Seven-crate workspace per docs/01-architecture.md. harness-core gets the
domain types (Session/Message/Part/ToolState), a broadcast EventBus, the
last-match-wins wildcard permission evaluator, and a SQLite storage actor
(dedicated thread + mpsc, JSON-blob rows) with roundtrip tests. All other
crates are compiling stubs. CI runs fmt/clippy -D warnings/test.
