World folder is the source of truth

- actor/<id>/ holds actor.wasm, actor.json, source/, public/, data/, versions/
- the broker boots by scanning actor/; a changed actor.wasm is an upgrade,
  a rejected one stays in versions/ with a reason and the files come back
- /actor hides every data/ folder
- subscriptions live in the subscriber's actor.json
- cargo installs the SDK and points sausage-actor at it; no build limits
- PROTOCOL.md

cli/Cargo.toml

@@ -18,6 +18,7 @@ include_dir = "0.7"
 serde = { version = "1", features = ["derive"] }
 serde_json = "1"
 tokio = { version = "1", features = ["full"] }
+toml_edit = "0.25"
 wasmtime = "49"
 wasmtime-wasi = "49"
 wasmtime-wasi-http = "49"