fix: redesign blockquotes as container blocks

[zbeyens]

🔀 PR #4941
🐛 Fixes #4898
🟢 95-100% confidence

Phase	🧪 Tests	🌐 Browser
Reproduced	✅	✅
Verified	🟢	🟢

🌐 Browser Check

• Opened http://localhost:3003/blocks/editor-ai and verified the seeded quote now renders a quoted list item plus a nested blockquote.
• Opened http://localhost:3003/docs/blockquote and verified the docs page shows nested blockquote example content plus the nested-block-content feature text.
• Opened http://localhost:3003/docs/autoformat and verified the nested > guidance and wrap-based blockquote rule snippet render.
• Opened http://localhost:3003/docs/examples/preview-markdown and verified the preview example shows > > Nested blockquote. and > - Quoted list item..
• Screenshots: /Users/zbeyens/.dev-browser/tmp/editor-ai-nested-blockquote.png, /Users/zbeyens/.dev-browser/tmp/blockquote-docs-nested.png, /Users/zbeyens/.dev-browser/tmp/autoformat-docs-nested.png, /Users/zbeyens/.dev-browser/tmp/preview-markdown-nested.png

✅ Outcome

• Keeps the blockquote redesign honest across the main apps/www surfaces instead of leaving stale single-paragraph quote examples behind.
• Updates editor seeds, blockquote docs, autoformat docs, preview markdown examples, and markdown paste guidance to show real container quotes with nested structure.
• Shows nested blockquotes and quoted list items in the examples users actually copy from.
• Regenerates the affected apps/www/public/r/*.json outputs so the rendered docs and demos match the source values.

⚠️ Caveat

• This is example/docs parity, not a full behavior matrix. It fixes the user-facing references that were still teaching the old flat quote shape.

🏗️ Design

• Chosen seam: update the primary examples and docs that define user expectations.
• Why not leave the old toy examples: once blockquote became a real container, flat examples turned into bad documentation.
• Why include markdown surfaces too: nested quotes and quoted lists are where users will notice the contract fastest, so the docs need to show the actual syntax.

🧪 Verified

• pnpm turbo build --filter=./apps/www
• pnpm turbo typecheck --filter=./apps/www
• pnpm lint:fix
• pnpm check

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[changeset-bot]

🦋 Changeset detected

Latest commit: a31b565

The changes in this PR will be included in the next version bump.

This PR includes changesets to release 4 packages

Name	Type
@platejs/basic-nodes	Major
@platejs/markdown	Major
@platejs/ai	Major
@platejs/docx-io	Major

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Project	Deployment	Actions	Updated (UTC)
plate	Ready	Preview, Comment	Apr 2, 2026 8:41am

[chatgpt-codex-connector]

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[chatgpt-codex-connector]

Split legacy \n\n quote separators into paragraph blocks

Legacy flat blockquotes from the previous model encoded paragraph breaks as consecutive newline text nodes, but this normalization path appends every non-block child into one inline run and wraps it into a single p. On existing persisted values like [{text:'A'},{text:'\n'},{text:'\n'},{text:'B'}], normalization collapses structure to one paragraph (A\n\nB) instead of two block children, so migration loses block-level paragraph boundaries and no longer preserves the intended container shape.

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