Limit Run target platforms to plugin declarations

platform_web/pages/ConsolePages.test.tsx

@@ -6,7 +6,7 @@ import { MaintenancePage } from "./MaintenancePage";
 import { PluginsPage } from "./PluginsPage";
 import { ProfileSettingsPage } from "./ProfileSettingsPage";
 import { ServerDetailPage } from "./ServerDetailPage";
-import { ServersPage } from "./ServersPage";
+import { runPlatformOptions, ServersPage } from "./ServersPage";
 import { UsersPage } from "./UsersPage";
 import runtimeTaskProgressSource from "../components/RuntimeTaskProgress.tsx?raw";
 import serverDeploymentWorkflowSource from "../components/ServerDeploymentWorkflow.tsx?raw";
@@ -17,7 +17,7 @@ import serverDetailPageSource from "./ServerDetailPage.tsx?raw";
 import type { PageComponentProps } from "../contracts/page";
 import { capabilitiesForRoles, type CurrentUserView } from "../contracts/workspace";
 import type { OperationTracker } from "../stores/operations";
-import type { UserResponse } from "../api/types";
+import type { GamePluginResponse, UserResponse } from "../api/types";
 
 const adminUser: CurrentUserView = {
   id: "user-admin",
@@ -62,6 +62,13 @@ function pageProps(params: PageComponentProps["params"] = {}): PageComponentProp
 }
 
 describe("first-party console pages", () => {
+  it("only offers plugin-declared run platforms", () => {
+    const plugin = { supportedOs: ["windows", "linux"] } as GamePluginResponse;
+
+    expect(runPlatformOptions(plugin, "darwin")).toEqual(["windows", "linux"]);
+    expect(runPlatformOptions(undefined, "windows")).toEqual(["windows"]);
+  });
+
   it("renders the platform overview with first-screen health modules", () => {
     const html = renderToStaticMarkup(<HomePage {...pageProps()} />);
 

platform_web/pages/ServersPage.tsx

@@ -981,7 +981,7 @@ function quickRuntimeDefaultsForPlugin(pluginId: string) {
   };
 }
 
-function runPlatformOptions(plugin: GamePluginResponse | undefined, fallback: string): string[] {
+export function runPlatformOptions(plugin: GamePluginResponse | undefined, fallback: string): string[] {
   const options = new Set<string>();
   const add = (value: string | undefined) => {
     const normalized = value?.trim().toLowerCase();
@@ -989,10 +989,13 @@ function runPlatformOptions(plugin: GamePluginResponse | undefined, fallback: st
       options.add(normalized);
     }
   };
-  add(fallback);
   plugin?.supportedOs?.forEach(add);
-  plugin?.runtimeProfiles?.lifecycleProfiles?.forEach((profile) => profile.platforms?.forEach(add));
-  ["linux", "windows", "darwin"].forEach(add);
+  if (options.size === 0) {
+    plugin?.runtimeProfiles?.lifecycleProfiles?.forEach((profile) => profile.platforms?.forEach(add));
+  }
+  if (options.size === 0) {
+    add(fallback);
+  }
   return [...options];
 }