cargo.build, the WASI test runner, the console, and core.notify ordering

- cargo.build (native): one source copy, tests under WASI, release
  build to /state/cargo/builds/<n>/, process groups killed on cancel.
  The host writes the SDK copy to /plugins/cargo/sdk/ at start.
- sausage test-runner: one instance per test, in parallel, with its own
  mount table (empty world, package folder at its path); answers
  core.lock, core.unlock, core.notify, core.log.
- The console: rustyline, notifications while typing, ls/cat through the
  process view, methods, ps, log, activate, revert, stop, kill.
- core.notify on stdout is handled in order, before the response.

cli/Cargo.toml

@@ -29,6 +29,10 @@ rusqlite = { version = "0.38", features = ["bundled"] }
 sausage-vfs = { version = "0.1.0", path = "../vfs" }
 sausage-interface = { version = "0.1.0", path = "../interface" }
 notify = "8.2.0"
+rustyline = "19"
+nix = { version = "0.31.3", features = ["signal", "process"] }
 
 [dev-dependencies]
+hyper = { version = "1.12.0", features = ["server", "http1"] }
+hyper-util = { version = "0.1.21", features = ["tokio"] }
 sausage-interface = { path = "../interface" }