fix: Prevent microphone auto-disconnect during calls and restore the removed microphone connected condition (#2597)

- Closes: #2590

src/card-controller/call/manager.ts

@@ -89,7 +89,7 @@ export class CallManager {
     // the call runs on the parent camera itself.
     const callCameraID = targetID === parentID ? undefined : targetID;
 
-    const existingCall = this._call;
+    let existingCall = this._call;
     if (
       existingCall &&
       existingCall.cameraID === parentID &&
@@ -120,6 +120,13 @@ export class CallManager {
       return false;
     }
 
+    // Re-read: another `start()` may have installed a session while the
+    // microphone connect was in flight. Acting on the reading from before the
+    // await would skip the supersede handling below, leaving that session's
+    // microphone marking and view state stranded with nothing able to undo
+    // them.
+    existingCall = this._call;
+
     // Store the previous view so it can be restored later. A call superseding
     // another inherits the earlier call's previous view -- the user never left
     // the call. `queryResults` are dropped (re-fetched fresh on restore).
@@ -152,6 +159,10 @@ export class CallManager {
       answered,
     };
 
+    // The microphone's own idle timeout knows nothing about calls, so without
+    // this the tracks would be stopped mid-conversation.
+    this._api.getMicrophoneManager().startUsing();
+
     this._api.getViewManager().setViewByParameters({
       ...(needsNavigation && {
         params: { view: 'live', camera: parentID },
@@ -250,6 +261,7 @@ export class CallManager {
     this._unansweredTimer.stop();
     if (this._call) {
       this._call = null;
+      this._api.getMicrophoneManager().stopUsing();
       this._api.getConditionStateManager().setState({ call: 'idle' });
     }
     this._api
@@ -279,6 +291,10 @@ export class CallManager {
     // and recurse.
     this._call = null;
 
+    // The call no longer needs the microphone, so the normal
+    // `disconnect_seconds` countdown restarts from here.
+    this._api.getMicrophoneManager().stopUsing();
+
     const viewManager = this._api.getViewManager();
 
     // Navigate back only on an explicit end, and only when the call actually

src/card-controller/microphone-manager.ts

@@ -25,6 +25,10 @@ export class MicrophoneManager {
   // it's created it will have the right mute status.
   private _desireMute = true;
 
+  // Whether something is actively using the microphone, and so when the
+  // connection can safely be closed.
+  private _inUse = false;
+
   constructor(api: CardMicrophoneAPI) {
     this._api = api;
   }
@@ -73,12 +77,28 @@ export class MicrophoneManager {
   }
 
   public disconnect(): void {
+    this._timer.stop();
     this._stream?.getTracks().forEach((track) => track.stop());
 
     this._stream = undefined;
     this._setState();
   }
 
+  // Marks the microphone as in use (e.g. by an in-progress call). It stays
+  // connected regardless of `disconnect_seconds` until `stopUsing`, since
+  // stopping the tracks under a user would silently cut their audio.
+  public startUsing(): void {
+    this._inUse = true;
+    this._timer.stop();
+  }
+
+  // Marks the microphone as no longer in use. It is idle again, so the
+  // disconnect countdown restarts from the full `disconnect_seconds`.
+  public stopUsing(): void {
+    this._inUse = false;
+    this._startDisconnectTimer();
+  }
+
   public getStream(): MediaStream | undefined {
     return this._stream ?? undefined;
   }
@@ -130,7 +150,7 @@ export class MicrophoneManager {
   private _startDisconnectTimer(): void {
     const microphoneConfig = this._api.getConfigManager().getConfig()?.live.microphone;
 
-    if (microphoneConfig?.always_connected) {
+    if (microphoneConfig?.always_connected || this._inUse) {
       return;
     }