The responsive change had moved `.pageIntro` off flex, which put the information
icon 1.06px off the subtitle's vertical centre and failed the existing geometry
assertion in `plugin-manager.e2e.ts`. Restore the flex row and the button's
`flex: none`, which keeps the 4px gap and the centring. The header still wraps
its action group onto another line, which is what this change is for.
Pin the wrap threshold in both header scenarios. Each records whether the action
group sits beside or below the heading, the plugin scenario asserts the wide and
narrow sides explicitly, and the plugin scenario launches its own scaffold so an
install task left by an earlier test cannot move the threshold between runs.
The page header keeps the title at its natural width and moves the New action
onto another line once the two no longer fit, so a narrow content column never
splits the title across lines.
Register the new browser scenario in both web programs: the host aggregate owns
files that boot the host spine, and the client-registered app project excludes
them.
The scenario asserts the title stays on one line, the action separates when the
column narrows, and focus survives the change.
Saafo