docs(rust-link): a sidecar refuses a plugin that names another server (D155)

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

rust-link/INSTALL.md

@@ -113,7 +113,7 @@ When you create a server from it:
 | Variable | |
 |---|---|
 | **Modding Framework** (`FRAMEWORK`) | `oxide` or `carbon`. `vanilla` installs no bridge and the server boots exactly as egg 18's |
-| **Runic Gateway: server id** (`RUSTLINK_SERVER_ID`) | The id on the website. Read **once**, when the plugin writes its first config; after that the file holds it and the site locks it, so changing the variable later changes nothing |
+| **Runic Gateway: server id** (`RUSTLINK_SERVER_ID`) | The id on the website. Read **once**, when the plugin writes its first config; after that the file holds it and the site locks it, so changing the variable later changes nothing — the launcher hands the sidecar the id from the plugin's config and says so in the console |
 | **Runic Gateway: sidecar port** (`RUSTLINK_WEB_PORT`) | **One of this server's allocations.** The panel does not tell a server which ports it holds, so a port that is not allocated binds but is never reachable |
 | **Runic Gateway: sidecar token** (`RUSTLINK_WEB_TOKEN`) | Leave blank: the sidecar generates one. Anyone who can see this server's startup variables can read a token typed here |
 | **Runic Gateway: bundle** (`RUNICGATEWAY_BUNDLE`) | Blank takes the current bundle. A tag pins one |
@@ -230,5 +230,6 @@ With the egg: reinstall to update (above); the console is the diagnosis.
 | The site says the sidecar is unreachable | The website cannot reach the URL: a loopback bind with the site elsewhere (see above), a firewall, or — on the egg — a sidecar port that is not one of the server's allocations |
 | The site answers `409` | The site's Rust module speaks another protocol than the bridge. Update whichever is behind (and see the note in *Before you begin*) |
 | `doctor`: *plugin connected — no, and the server is running* | The plugin did not compile or cannot reach its sidecar. The server console names a compile error; the plugin's `Port` must equal the sidecar's game port |
+| The sidecar logs *refusing a plugin that names another server* | Two servers dial one sidecar: a plugin's `Port` is another server's game port. Correct that plugin's `Port` (in its config) and reload it. Nothing it sent was stored |
 | `doctor`: *not the file that was deployed* | The plugin was edited by hand. `update --game rust` puts the released one back |
 | The egg's console prints a new token after every boot | Only a sidecar older than the first Rust-Link release does this; reinstall the server |

rust-link/INTEGRATION.md

@@ -197,10 +197,11 @@ Each pair is fully independent: its own ports, its own `sidecar.toml`, its own d
 own token, its own row on the website.
 
 Set `[game].server_id` in each `sidecar.toml` to match that server's plugin config. It is a
-**cross-check**, not a second source of truth — the plugin's announcement wins — and it exists to
+**cross-check**, not a second source of truth, and it exists to catch exactly one mistake: two game
-catch exactly one mistake: two game servers pointed at one sidecar by a copied config, which is
+servers dialling one sidecar, which is silent in every other design and produces one server's
-silent in every other design and produces one server's history under another's name. When it fires
+history under another's name. When it fires, the sidecar refuses the plugin that names the other
-you get a warning naming both ids.
+server, before anything it sent is stored, and logs an `ERROR` naming both ids; that plugin retries
+every few seconds until its `Port` is corrected. The installer and the egg set it for you.
 
 ---
 

rust-link/PROTOCOL.md

@@ -324,9 +324,13 @@ Two things about those are load-bearing:
   working directory. A service manager's working directory must not decide where the database lands
   — on Windows that can be `%SystemRoot%\System32`, or a silently redirected VirtualStore copy.
 - **`[game].server_id` is a cross-check, not a second source of truth.** The plugin announces its own
-  `serverId` and that is the authority; when both are set and they disagree, the sidecar logs the
+  `serverId` and that is the authority for what a server is called. When `server_id` is set, the
-  disagreement loudly and keeps the plugin's. Two game servers pointed at one sidecar by a copied
+  sidecar **refuses a plugin that names another server**: it closes the connection on the first
-  config is the mistake this catches, and it is silent in every other design.
+  frame that disagrees, before that frame is filed, and logs both ids at `ERROR` (D155). Until a
+  frame has named this server, no command is sent to the peer and `/health` does not report a
+  plugin connected. Blank, nothing is checked. Two game servers dialling one sidecar is the mistake
+  this catches. It was a warning that kept the plugin's id until phase 18, when a walk showed the
+  cost: one server's history filed under another's name, on the website (PLAN.md §34.5).
 
 `rust-link-sidecar --print-config` resolves the configuration exactly as a normal start would —
 writing the file and generating the token if they are missing — and prints it as JSON on stdout,