Say outright whether the profile is ours to change

Whether to offer the profile settings was inferred from whether the host
could close Element Call. For a component with no host bridge — the
default — nothing could, so an embedded Element Call let the user edit
the profile of an account that belongs to the host application.

`HostBridge.supportsProfileChanges` states it directly: true standalone,
where Element Call signed the user in itself; false for a widget's host
and for anything embedding the component (which sets it itself, since
the client it hands over is its own). The profile tab and the profile
shortcut follow that. What a host's ability to close us still decides —
what to show after the call ends — is a question about who owns our
lifetime, and stays keyed on `close`.

Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>

component/dev/DevHostBridge.ts

@@ -10,7 +10,7 @@ import { NEVER, Subject } from "rxjs";
 import {
   type DeviceMuteRequest,
   type DeviceMuteState,
-  type HostBridge,
+  type ElementCallHostBridge,
   type HostRequest,
 } from "../index";
 
@@ -19,7 +19,7 @@ import {
  * so that the harness can watch both directions of the conversation between
  * Element Call and its host.
  */
-export interface DevHostBridge extends HostBridge {
+export interface DevHostBridge extends ElementCallHostBridge {
   /** Tells Element Call the host has changed theme. */
   requestTheme(name: string): void;
   /** Tells Element Call to leave the call. */

component/index.tsx

@@ -100,6 +100,14 @@ export {
  */
 export type ElementCallConfiguration = Partial<UrlParams>;
 
+/**
+ * What a host embedding Element Call implements to talk to it. This is the
+ * {@link HostBridge} less what Element Call already knows about such a host:
+ * the account is the host's, since the client is, so the profile is not
+ * Element Call's to change.
+ */
+export type ElementCallHostBridge = Omit<HostBridge, "supportsProfileChanges">;
+
 export interface ElementCallProps {
   /**
    * The client to place the call with. Element Call does not authenticate
@@ -132,7 +140,7 @@ export interface ElementCallProps {
    * joined or hung up, to be asked to keep the call on screen, and so on.
    * Without one, Element Call assumes it has no host to talk to.
    */
-  hostBridge?: HostBridge;
+  hostBridge?: ElementCallHostBridge;
 }
 
 /**
@@ -181,8 +189,19 @@ export const ElementCall: FC<ElementCallProps> = ({
   roomId,
   intent = UserIntent.JoinExistingCall,
   config,
-  hostBridge = nullHostBridge,
+  hostBridge: suppliedHostBridge = nullHostBridge,
 }): ReactNode => {
+  // Whatever the host says or does not say, the account is its own: it signed
+  // the user in and handed us the client. So Element Call never offers to edit
+  // the profile from inside a component.
+  const hostBridge = useMemo(
+    (): HostBridge => ({
+      ...suppliedHostBridge,
+      supportsProfileChanges: false,
+    }),
+    [suppliedHostBridge],
+  );
+
   // The container is what Element Call decorates and portals into, so nothing
   // inside can render until we have it.
   const [container, setContainer] = useState<HTMLDivElement | null>(null);