docs(maestro): describe the single-host architecture

Rewrites CLAUDE.md as the current-architecture reference, drops the
registry from INSTALL/PRODUCT/DESIGN and the web README, deletes the
registry Dockerfile, and marks the dated design specs superseded where
they describe the registry, JWT auth, or cross-host attach.

The installer loses its configure step — every config field now has a
default, so a daemon starts with no config file at all.

crates/maestro-protocol/Cargo.toml

@@ -5,7 +5,7 @@ edition.workspace = true
 license.workspace = true
 repository.workspace = true
 publish.workspace = true
-description = "Shared wire types for Maestro daemon/registry/client communication"
+description = "Shared wire types for Maestro daemon/client communication"
 
 [dependencies]
 chrono.workspace = true