Proposal for Reusable content snippets (source blocks + reference embeds)

Problem Content gets copy-pasted across documents today (onboarding steps, legal boilerplate, standard warnings, team policies). When the source changes, every copy silently drifts out of date, and there's no way to find "everywhere this text is used" short of a manual search. Proposal Two new editor primitives: • Snippet source — a block-level container, wrapping one or more blocks of content, tagged with a stable id. Lives inline in a document's normal content, same as any other block. • Snippet reference — an atomic node placed on other pages that points at a snippet source by id, renders a cached preview, and resolves live source content on demand. The source's actual text stays exactly once, inside the one document that owns it. Every other document holds only a small pointer node, not a copy of the text. Precedent already in this codebase This isn't a new pattern for Outline — it's a recombination of two things…