Fix voice mode connecting spinner getting stuck indefinitely

[Copilot]

Description

Pressing the voice mode button while a chat session is in progress could leave the toolbar spinner (agentsVoice.connecting) spinning forever with no effect and no feedback.

Root cause: VoiceSessionController.connect() armed its timeout watchdog only after several awaits (getSessions('github'), transcript-store loads, voiceClientService.connect()). If any of that awaited work hung — plausible when the auth provider is busy servicing an in-progress request — the watchdog was never armed, so isConnecting stayed true indefinitely. Re-clicking did nothing since connect() early-returns while connecting, and no failure path surfaced feedback.

Changes (voiceSessionController.ts):

• Connect watchdog armed up front — a _connectWatchdog (MutableDisposable, 10s) is armed before any awaited work, and re-armed immediately before the WebSocket handshake so the handshake gets a fresh window regardless of auth latency. Cleared on a successful handshake and in disconnect().
• Feedback on timeout — on expiry the watchdog calls disconnect() and shows a warning notification ("Voice mode could not connect. Please try again.") instead of silently reverting.
• Late-connection guard — after the awaited auth/transcript work, connect() bails if isConnecting was already reset (by the watchdog or an explicit disconnect), avoiding opening a connection the user no longer expects.
• Replaces the previous post-await inline setTimeout, which only covered the handshake, with a watchdog spanning the whole connect lifecycle.

private _armConnectWatchdog(): void {
    this._connectWatchdog.value = disposableTimeout(() => {
        if (!this._isConnecting.get() || this._isConnected.get()) {
            return;
        }
        this.disconnect();
        this.notificationService.notify({
            severity: Severity.Warning,
            message: localize('voice.connectFailed', "Voice mode could not connect. Please try again."),
        });
    }, VoiceSessionController._CONNECT_TIMEOUT_MS);
}

Adds an INotificationService dependency to the controller (registered singleton; no direct instantiation sites affected).

[Copilot]

Pull request overview

Prevents voice mode’s connecting spinner from hanging indefinitely.

Changes:

• Adds a 10-second connection watchdog with timeout feedback.
• Cancels late connections after timeout or disconnect.
• Clears the watchdog after successful connection or disconnection.

Show a summary per file

File	Description
voiceSessionController.ts	Adds watchdog lifecycle, timeout notification, and late-connection handling.

Review details

• Files reviewed: 1/1 changed files
• Comments generated: 2
• Review effort level: Medium