Summary

Adds a matchNodes callback for the y-prosemirror syncPlugin diff and a comprehensive E2E test suite for suggestion-mode collaboration scenarios.

Changes

Core: blockMatchNodes node-pairing policy

• packages/core/src/y/extensions/blockMatchNodes.ts (new) — schema-specific matchNodes callback passed to lib0/delta.diff via @y/prosemirror. A blockContainer whose first block-content child changes type (e.g. paragraph → heading) is treated as a different node, so the diff replaces the whole container instead of producing two block-contents in one container (which would be schema-invalid).
• packages/core/src/y/extensions/YSync.ts — wires blockMatchNodes into the syncPlugin options.

Core: suggestion mark attribution improvements

• packages/core/src/extensions/tiptap-extensions/Suggestions/SuggestionMarks.ts — suggestion marks (y-attributed-insert, y-attributed-delete, y-attributed-format) now carry userIds: string[], timestamp: number, and (for format marks) format metadata instead of a single numeric id. Adds data-description tooltip attributes with human-readable "Inserted/Deleted/Modified by X on Y" strings.

Core: UniqueID fix for suggestion-deleted nodes

• packages/core/src/extensions/tiptap-extensions/UniqueID/UniqueID.ts — nodes carrying the y-attributed-delete mark (suggestion-mode tombstones from type changes) are now excluded from duplicate-ID detection so the surviving block keeps its original ID.

Patches

• patches/lib0@1.0.0-rc.14.patch (new) — patches lib0/delta.diff to accept an optional matchNodes callback, forwarded through applyChangesetToDelta to control node pairing during diffing.
• patches/@y__prosemirror@2.0.0-2.patch (updated) — threads the matchNodes option from syncPlugin config through to the lib0/delta.diff call.
• Removes obsolete patches/@y__y@14.0.0-rc.16.patch and patches/lib0@1.0.0-rc.13.patch (superseded by lib0 rc.14 upgrade + new patch).

Versioning: YHub adapter

• packages/core/src/y/versioning/yhub.ts (new) — createYHubVersioningEndpoints() factory that implements VersioningEndpoints against the YHub HTTP API (activity listing, changeset retrieval, rollback, snapshot naming).

E2E test suite (tests/src/end-to-end/y-prosemirror/)

12 new test files covering suggestion-mode collaboration with screenshot assertions:

Test fixtures in fixtures/ provide reusable suggestion-mode and concurrent-suggestion-mode editor setups.

Example: multi-doc versioning demo

• examples/07-collaboration/14-multi-doc-versioning/ — full working example demonstrating the YHub versioning adapter with document listing, history sidebar, and version restore.

Impact

• The matchNodes policy prevents schema-invalid states when changing block types under suggestion mode — this was a correctness bug.
• Suggestion mark metadata is richer (multiple user IDs, timestamps, format details) but the attribute shape changed (id → userIds/timestamp), which is a breaking change for any code inspecting suggestion mark attributes directly.
• The lib0 patch target changed from rc.13 to rc.14.