[offvault]

Before submitting your pull request

• I agree to license my code under the MPL 2.0 license.
• I rebased my work on top of the main branch.
• I ran npm test and all tests passed.
• I added test coverages if relevant.

Description

Fixes a major UX friction point where users can easily get stuck in cross-container OAuth flows (such as Google Sign-In) because there is no explicit way to clear an "Always open in..." assignment from the popup or page action menu.

This PR adds a "Default Container" option to both the popup always-open-in menu and the pageAction menu. Clicking this option clears the site's container assignment and safely reloads the tab in the default container.

Implementation Details:

• Added a removeAlwaysOpenInContainer() utility in utils.js.
• Prevented a race condition where the webRequest listener intercepts the newly created default tab before the assignment is cleared from storage. The rule is now cleanly removed before the new tab is created, and then the success message is routed to the new tab.
• Rendered the "Default Container" menu item identically to how it is handled in the "Reopen This Site in..." menu.
• Updated assignment.test.js and 940.test.js to account for the new Default Container menu item to ensure tests continue passing.

Type of change

• Bug fix
• New feature
• Major change

[dannycolin]

This PR adds a "Default Container" option

By "default container", are you referring to the cookies & site data for regular tabs that aren't in a container?