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. */