"Menu title" literal string shown for filtering disclosure

[janbrasna]

Describe the bug
In some circumstances, instead of "All products" details disclosure, I get literally "Menu title" emitted there.

Preconditions
<1024px narrow window

Steps to reproduce

1. Go to https://support.mozilla.org/en-US/kb/view-web-pages-reader-view-firefox-ios
2. Scroll to get searchbox in sticky nav
3. Search for "test"
4. Check what product or topic you're filtered to, or try to change the filter.

Expected behavior
Like on https://support.mozilla.org/en-US/ search for "test" and note "Filter by product" › "All products".

Actual behavior
Starting from a product page like https://support.mozilla.org/en-US/kb/view-web-pages-reader-view-firefox-ios searching for "test" yields "Filter by product" › "Menu title".

Screenshots/Screencasts

Desktop (please complete the following information):

• macOS 15, FXDE

Additional context
This seems to appear in https://github.com/mozilla/kitsune/blob/fec4bc4a/kitsune/sumo/static/sumo/tpl/search-results.njk#L8 — and is probably intended to get replaced on init with a selection according to https://github.com/mozilla/kitsune/blob/fec4bc4a/kitsune/sumo/static/sumo/js/protocol-details-init.js#L21