feat: Disable session lock when running in element-desktop (#30643)

* feat: Disable session lock when running in element-desktop

* feat: Use Platform abstractions over direct invocation for session lock.

* fix: Remove window.electron checks from session lock methods.

* docs: Remove extraneous doc comments.

* feat: Convert BasePlatform session methods to abstract methods.

* fix: Check for PlatformPeg instance in session lock.

* fix: Remove async marker from checkSessionLockFree

src/BasePlatform.ts

@@ -508,4 +508,19 @@ export default abstract class BasePlatform {
      * Begin update polling, if applicable
      */
     public startUpdater(): void {}
+
+    /**
+     * Checks if the current session is lock-free, i.e., no other instance is holding the session lock.
+     * Platforms that support session locking should override this method.
+     * @returns {boolean} True if the session is lock-free, false otherwise.
+     */
+    public abstract checkSessionLockFree(): boolean;
+    /**
+     * Attempts to acquire a session lock for this instance.
+     * If another instance is detected, calls the provided callback.
+     * Platforms that support session locking should override this method.
+     * @param _onNewInstance Callback to invoke if a new instance is detected.
+     * @returns {Promise<boolean>} True if the lock was acquired, false otherwise.
+     */
+    public abstract getSessionLock(_onNewInstance: () => Promise<void>): Promise<boolean>;
 }