[Real-time Collaboration] Fix sync issue on refresh (#76017)

* Add (passing) e2e reproduction for refresh and disconnect issue

* Reproduce the bug by actually typing in the document

* Include current doc state as UPDATE in initial queue alongside SYNC_STEP_1

Root Cause: createYjsDoc() in utils.ts calls stateMap.set(VERSION_KEY, CRDT_DOC_VERSION) which creates the first Yjs operation (clock=0) on the new Y.Doc. This happens before registerRoom() attaches the onDocUpdate handler. As a result, this operation is never captured as a regular UPDATE and never individually sent to peers.

After a page refresh, User A gets a new client ID. The stateMap.set creates clock=0 under this new ID, but it’s invisible to the sync system. When User A types, all operations start at clock=1+ and depend on clock=0. User B receives the typing updates but can’t integrate them because the missing dependency (clock=0) was never sent.

Why it’s flaky: Occasionally, the server triggers a COMPACTION (full state snapshot) that includes clock=0, resolving the issue within the test timeout. When no compaction arrives in time, the test fails.

Fix: In registerRoom(), include the current doc state as an UPDATE in the initial queue alongside the SYNC_STEP_1. This ensures any pre-existing operations (like the VERSION_KEY set) are sent to peers when the queue is resumed.

* Delay setting state instead of sending duplicative update

* Remove comment

---------

Co-authored-by: alecgeatches <[email protected]>
Co-authored-by: chriszarate <[email protected]>

Source: WordPress/gutenberg@dbddb42

Author: maxschmeling

README.md

@@ -5,12 +5,12 @@ This is a duplicate of the [WordPress/Gutenberg](https://github.com/WordPress/gu
 You are currently viewing the version build from the source:
 
 * Branch: `wp/7.0`
-* Commit: [WordPress/Gutenberg@`f23578a2e9a`](https://github.com/WordPress/gutenberg/commit/f23578a2e9a23c5518bce93aaac34330e8afefd5), [Browse files](https://github.com/WordPress/gutenberg/tree/f23578a2e9a23c5518bce93aaac34330e8afefd5)
+* Commit: [WordPress/Gutenberg@`dbddb42003c`](https://github.com/WordPress/gutenberg/commit/dbddb42003cf34944b69e4c58725566a96bcddfa), [Browse files](https://github.com/WordPress/gutenberg/tree/dbddb42003cf34944b69e4c58725566a96bcddfa)
 
 > [!NOTE]
 > This readme file has replaced the original version included in the upstream repository.
 >
-> The [original `README.md` file](https://github.com/WordPress/gutenberg/blob/f23578a2e9a23c5518bce93aaac34330e8afefd5/README.md) file for this commit can be found in the upstream repository.
+> The [original `README.md` file](https://github.com/WordPress/gutenberg/blob/dbddb42003cf34944b69e4c58725566a96bcddfa/README.md) file for this commit can be found in the upstream repository.
 
 ## Pupose
 

build/modules/registry.php

@@ -13,9 +13,14 @@
 		'asset' => 'interactivity/index.min.asset.php',
 	),
 	array(
-		'id' => '@wordpress/a11y',
-		'path' => 'a11y/index',
-		'asset' => 'a11y/index.min.asset.php',
+		'id' => '@wordpress/interactivity-router',
+		'path' => 'interactivity-router/index',
+		'asset' => 'interactivity-router/index.min.asset.php',
+	),
+	array(
+		'id' => '@wordpress/interactivity-router/full-page',
+		'path' => 'interactivity-router/full-page',
+		'asset' => 'interactivity-router/full-page.min.asset.php',
 	),
 	array(
 		'id' => '@wordpress/latex-to-mathml',
@@ -27,16 +32,6 @@
 		'path' => 'latex-to-mathml/loader',
 		'asset' => 'latex-to-mathml/loader.min.asset.php',
 	),
-	array(
-		'id' => '@wordpress/interactivity-router',
-		'path' => 'interactivity-router/index',
-		'asset' => 'interactivity-router/index.min.asset.php',
-	),
-	array(
-		'id' => '@wordpress/interactivity-router/full-page',
-		'path' => 'interactivity-router/full-page',
-		'asset' => 'interactivity-router/full-page.min.asset.php',
-	),
 	array(
 		'id' => '@wordpress/vips/worker',
 		'path' => 'vips/worker',
@@ -47,21 +42,26 @@
 		'path' => 'vips/loader',
 		'asset' => 'vips/loader.min.asset.php',
 	),
+	array(
+		'id' => '@wordpress/a11y',
+		'path' => 'a11y/index',
+		'asset' => 'a11y/index.min.asset.php',
+	),
 	array(
 		'id' => '@wordpress/abilities',
 		'path' => 'abilities/index',
 		'asset' => 'abilities/index.min.asset.php',
 	),
-	array(
-		'id' => '@wordpress/route',
-		'path' => 'route/index',
-		'asset' => 'route/index.min.asset.php',
-	),
 	array(
 		'id' => '@wordpress/core-abilities',
 		'path' => 'core-abilities/index',
 		'asset' => 'core-abilities/index.min.asset.php',
 	),
+	array(
+		'id' => '@wordpress/route',
+		'path' => 'route/index',
+		'asset' => 'route/index.min.asset.php',
+	),
 	array(
 		'id' => '@wordpress/connectors',
 		'path' => 'connectors/index',