Draft: Convert google_cloud bootstraps to initVueApp

What does this MR do and why?

Stacked on !247299 (merged) (the boring initVueApp wave) — retarget to master when it merges. The six google_cloud bootstraps forward attribute bags that are really props (the attrs-as-props shape flagged in the wave review), so they are kept out of the mechanical wave.

Stays Draft until the preparation lands: the plan is a preparatory commit that makes the google_cloud components declare real props, after which these conversions become the plain boring shape and the current normalizeRender workaround disappears.

Current content is the behavior-preserving CI-proven state from the pre-split !247299 (merged).

MR acceptance checklist

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