feat: expose canonical module display URLs

packages/module-ui-host/tests/load-module-ui.test.ts

@@ -52,6 +52,7 @@ export default {
 function hostContext(requested: string[], moduleId = "announcements"): ModuleUiHostContext {
   return {
     contributions: NO_MODULE_UI_CONTRIBUTIONS,
+    display: undefined,
     moduleId,
     api: {
       async request(path) {

packages/module-ui-host/tests/real-artifact.test.ts

@@ -33,6 +33,7 @@ let artifactSource: string;
 function ekklesiaContext(requested: string[]): ModuleUiHostContext {
   return {
     contributions: NO_MODULE_UI_CONTRIBUTIONS,
+    display: undefined,
     moduleId: "example",
     api: {
       async request(pathname) {
@@ -50,6 +51,7 @@ function ekklesiaContext(requested: string[]): ModuleUiHostContext {
 function standaloneContext(requested: string[]): ModuleUiHostContext {
   return {
     contributions: NO_MODULE_UI_CONTRIBUTIONS,
+    display: { url: "https://example.test/display" },
     moduleId: "example",
     api: {
       async request(pathname) {

packages/module-ui-sdk/src/host-context.ts

@@ -75,6 +75,14 @@ export interface ModuleUiHostContext {
   /** The module this UI belongs to, as the host knows it. Supplied so a module never has to hardcode
    * or re-derive its own identity from a URL. */
   readonly moduleId: string;
+  /**
+   * The host-owned public page for this module's dedicated display, when one exists.
+   *
+   * The URL is already absolute and deployment-correct. A module may show, open, or copy it, but
+   * must never construct a platform route or combine its own id with a browser origin. A standalone
+   * host can provide its own display page here without imitating Ekklesia's routing.
+   */
+  readonly display: ModuleUiDisplayLocation | undefined;
   /** The only supported way for module UI to reach its own backend. See {@link ModuleUiApiClient}. */
   readonly api: ModuleUiApiClient;
   /** Who is viewing, for presentation decisions only. See {@link ModuleUiPrincipal} for why this is
@@ -96,6 +104,10 @@ export interface ModuleUiHostContext {
   readonly contributions: ModuleUiContributions;
 }
 
+export interface ModuleUiDisplayLocation {
+  readonly url: string;
+}
+
 /**
  * A module UI's access to its own module's HTTP API, addressed **relative to the module's own API
  * root** — never as an absolute path.

packages/module-ui-sdk/tests/module-ui-contract.test.ts

@@ -186,6 +186,7 @@ describe("the same module UI artifact hosted by two different hosts", () => {
       requestedUrls,
       context: {
         contributions: NO_MODULE_UI_CONTRIBUTIONS,
+        display: undefined,
         moduleId,
         api,
         principal: { kind: "anonymous" },
@@ -211,6 +212,7 @@ describe("the same module UI artifact hosted by two different hosts", () => {
       requestedUrls,
       context: {
         contributions: NO_MODULE_UI_CONTRIBUTIONS,
+        display: { url: "https://announcements.example.org/display" },
         moduleId,
         api,
         principal: { kind: "anonymous" },