fix(calls): the call bar shows "Call disconnected" and reconnects when sync is back (#318)

After a homeserver stall Element Call showed "Connection lost" while the
call bar still looked joined. Handle the fork's io.lotus.call_error:
show "Call disconnected" with a Reconnect button (io.lotus.reconnect),
and reconnect automatically once sync is back.

Fixes #318

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_017PCb59uY3UKqDqt7B6hzd5

src/app/plugins/call/CallControl.ts

@@ -3,6 +3,7 @@ import { EventEmitter } from 'events';
 import { CallControlState } from './CallControlState';
 import { ElementMediaStateDetail, ElementMediaStatePayload, ElementWidgetActions } from './types';
 import { canDelegateCapability } from './utils';
+import { CallErrorState, parseCallError } from './callError';
 
 export enum CallControlEvent {
   StateUpdate = 'state_update',
@@ -54,6 +55,8 @@ export function parseForkHotkeyReport(data: unknown): ForkHotkeyReport | null {
   };
 }
 
+export const CALL_ERROR_CHANGED = 'call_error_changed';
+
 export class CallControl extends EventEmitter implements CallControlState {
   private state: CallControlState;
 
@@ -205,6 +208,27 @@ export class CallControl extends EventEmitter implements CallControlState {
     return this._audioOutputId;
   }
 
+  // [Gitea #318] The fork's error page ("Connection lost") is up; the host
+  // kept showing the call as joined with controls that did nothing.
+  private _callError: CallErrorState = null;
+
+  public get callError(): CallErrorState {
+    return this._callError;
+  }
+
+  /** The fork's `io.lotus.call_error` report. */
+  public onCallError(data: unknown) {
+    const next = parseCallError(data);
+    if (next === undefined) return;
+    this._callError = next;
+    this.emit(CALL_ERROR_CHANGED);
+  }
+
+  /** Press the fork's Reconnect / Try again. */
+  public reconnect(): void {
+    this.call.transport.send('io.lotus.reconnect', {}).catch(() => undefined);
+  }
+
   public setAudioOutput(deviceId: string): void {
     this._audioOutputId = deviceId;
     this.sendAudioOutput(deviceId);