Adds content.published_block_configs: the host returns the stored
content JSON of every block with a given key inside currently
published page snapshots. Restores server-authoritative per-block
enforcement for sandboxed guests (calcomblock's captcha requirement
was inert under wasm — blockConfig hardcoded nil because no capability
exposed published block content). Breaking: content.Content gains a
method; the cms adapter implements it in the paired bump.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
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