Fixes memory leak in ScreenInstrumentation

[mghaznav]

Summary

Fixes a memory leak and notification subscription race in ScreenInstrumentation.

Problem

1. Memory Leak: The background notification-listening Task in ScreenInstrumentation.configure() strongly captured self inside an infinite for await loop and was never stored or cancelled. reportingTask also strongly captured self across its 50ms debounce sleep. As a result, ScreenInstrumentation instances never deallocated and continued processing notifications indefinitely.
2. Missed Early Notifications: NotificationCenter.default.notifications(named: .screenTrackingEvent) was created asynchronously inside Task(priority: .utility), causing notifications posted immediately after ScreenInstrumentation.init to be missed before the task started.

Fix

1. Create the NotificationCenter.Notifications stream synchronously in init so observer registration happens immediately, eliminating the Task.sleep workarounds in tests.
2. Store the notification-listening task in an actor-isolated listeningTask property, capture [weak self] in both listeningTask and reportingTask, and cancel both tasks in deinit.
3. Add a unit test verifying that ScreenInstrumentation deallocates and stops processing notifications when released.

[gemini-code-assist]

Using Gemini Code Assist

The full guide for Gemini Code Assist can be found on our documentation page, here are some quick tips.

Invoking Gemini

You can request assistance from Gemini at any point by creating a comment using either /gemini <command> or @gemini-code-assist <command>. Below is a summary of the supported commands on the current page.

Feature	Command	Description
Code Review	/gemini review	Performs a code review for the current pull request in its current state.
Pull Request Summary	/gemini summary	Provides a summary of the current pull request in its current state.
Comment	@gemini-code-assist	Responds in comments when explicitly tagged, both in pull request comments and review comments.
Help	/gemini help	Displays a list of available commands.

Customization

To customize the Gemini Code Assist for GitHub experience, repository maintainers can create a configuration file and/or provide a custom code review style guide (such as PEP-8 for Python) by creating and adding files to a .gemini/ folder in the base of the repository. Detailed instructions can be found here.

Limitations & Feedback

Gemini Code Assist may make mistakes. Please leave feedback on any instances where its feedback is incorrect or counterproductive. You can react with 👍 and 👎 on @gemini-code-assist comments. If you're interested in giving your feedback about your experience with Gemini Code Assist for GitHub and other Google products, sign up here.

[mghaznav]

/gemini review

[danger-firebase-ios]

	1 Warning
⚠️	Did you forget to add a changelog entry? (Add #no-changelog to the PR description to silence this warning.)

Generated by 🚫 Danger

[gemini-code-assist]

Code Review

This pull request refactors ScreenInstrumentation to manage its asynchronous tasks, introducing a listeningTask for notification tracking, handling deinitialization to cancel active tasks, and adding a unit test to verify clean deallocation. The review feedback suggests simplifying the initialization of ScreenInstrumentation by spawning the listeningTask synchronously inside init rather than wrapping it in an outer Task that calls configure(with:). This change would eliminate unnecessary actor hops and allow for the removal of a sleep buffer in the deallocation unit test.

[ncooke3]

Consideration: evaluate if configure's implementation needs to handle multiple callers, to prevent tasks getting overwritten