fix(rust): the handoff says what the run did, not that a link exists (D156)

`install --game rust` ended every instance with "Rust server "alpha" is
connected to its sidecar" — printed unconditionally, before the plugin had
dialled anything, on a stopped server where it had not even loaded, and
beside "No service was registered, so nothing is listening yet". The
phase 18 walk read it as a claim and then found beta's plugin connected to
the wrong sidecar.

It now reads "Rust server "alpha" is set up." followed by either "The
plugin loads now; `doctor --game rust --server-id alpha` confirms it
connected." or "The plugin connects when the server next starts.".

The top-level --help no longer describes `install` as the uo-link sidecar
and overlay for both games, and says what `uninstall` removes for Rust.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01E14m6SuuY6i1vASFeGDBeY

src/cli.rs

@@ -134,13 +134,14 @@ Gateway website.
 Usage: runicgateway-installer <COMMAND> [OPTIONS]
 
 Commands:
-  install      Deploy the plugin overlay, install the uo-link sidecar and its
-               service, record what was deployed, and print the values the
-               website needs.
+  install      Deploy the game-side plugin (the ServUO overlay, or the Rust
+               plugin), install the sidecar and its service, record what was
+               deployed, and print the values the website needs.
   doctor       Diagnose an existing deployment end to end.
   update       Re-resolve the bundle and move both components to it.
   uninstall    Remove what the installer exclusively owns. Never edits the
-               ServUO tree — it prints what to remove there.
+               ServUO tree — it prints what to remove there. For Rust it
+               removes only its own plugin file and keeps the plugin config.
 
 Options:
       --game <servuo|rust>           Which game's shard side. Default servuo.