Research Store-backed extension update prompts

[hoangsvit]

Context

Browsers normally update Store-installed extensions automatically, but Gmail Alias Toolkit may benefit from a non-blocking prompt when a newer Store version is available.

A prototype currently exists in draft PR #83. Keep that pull request isolated and do not merge it until the Store-hosted update flow has been verified end to end.

Questions to answer

• Does runtime.requestUpdateCheck() behave consistently across Chrome, Edge, Brave, and Firefox?
• Does update_available reliably include the target version on each browser?
• What happens when the popup closes before runtime.onUpdateAvailable fires?
• Should the banner rely on browser runtime APIs, Store metadata, or both?
• How should partial/staged Store rollouts be handled?
• Can the feature be tested safely with a private Chrome Web Store item and an AMO test listing?
• How should manual ZIP / Load unpacked installations be handled, since they cannot use Store-managed updates?
• Is a custom prompt valuable enough compared with relying on automatic browser updates?

Required research setup

Chrome-family browsers

• Create a private or trusted-testers Beta Store item.
• Publish an older version and install it from the Store.
• Publish a newer version.
• Verify requestUpdateCheck() results.
• Verify download and onUpdateAvailable lifecycle.
• Verify runtime.reload() applies the downloaded update.
• Test throttling and staged rollout behavior.

Firefox

• Prepare an AMO test path or equivalent safe environment.
• Repeat the older-version to newer-version update test.
• Compare runtime status and lifecycle behavior with Chromium.

Acceptance criteria

• End-to-end update is verified using Store-installed builds, not Load unpacked.
• Chrome-family and Firefox differences are documented.
• The data source for available version is decided.
• Snooze/check frequency behavior is confirmed.
• Manual installation behavior is documented.
• A clear go/no-go decision is recorded before PR research: evaluate Store-backed extension update prompts #83 is marked ready.

Related work

• Draft prototype: research: evaluate Store-backed extension update prompts #83
• The prototype currently includes a banner, 24-hour check interval, seven-day snooze, localized copy, state handling, and unit tests.

Status

Research only. Do not merge the prototype until this issue's acceptance criteria are completed.