[web/document-updater] display preview for accepted/rejected tracked changes (#36240)

* [web] add preview payload to track-change notification types

* [doc-updater] pass accepted/rejected change data through to web for previews

* [web] snapshot change preview onto accepted/rejected notifications

* [web] render resolved change previews instead of accepted/rejected count lines

* [web] add unit coverage for accepted/rejected change preview flow

* fix: notification carries multiple previews per accept/reject batch; extract shared group helper

* fix: one preview per accept/reject action, drop adjacency grouping

* fix: move buildResolvedChangePreviews out of the email builder class

* fix: type error, make tests more explicit

* fix: render resolver below preview

* fix: overflow text, alignment

* fix: test error

* fix: resolved count

* [document-updater/web] send sparse change preview instead of full doc lines

* fix: store sparse preview, hydrate at render, drop CE gate

* fix: advance slice cursor past tracked-delete text in sparse preview

* fix: inline buildChangeGroupPreview

* fix: changePreviewBuilder -> sparseChangePreview

* fix: rm change_contributors

* fix: copilot flagged testing issues

* fix: hydrate and truncate change preview at write time

* fix: avoid materializing full doc text when slicing preview window

* fix: update reject preview test to hydrated shape

* fix: accepted delete removing context

* [document-updater/web] split resolved change previews into one per change cluster

* fix: narrow cluster userIds to string[] for typecheck

* feat: updating to use zod schema for previews

---------

Co-authored-by: Jimmy Domagala-Tang <jimmy.domagala-tang@overleaf.com>
GitOrigin-RevId: 0740713c715a61a220180f353e497b27da6a5b0f

services/document-updater/test/unit/js/HttpController/HttpControllerTests.js

@@ -692,9 +692,20 @@ describe('HttpController', function () {
     describe('successfully with a single change', function () {
       beforeEach(async function () {
         this.changeContributors = ['user-id-1', 'user-id-2']
-        this.DocumentManager.promises.acceptChangesWithLock.resolves(
-          this.changeContributors
-        )
+        this.previews = [
+          {
+            sectionPath: [],
+            startLine: 1,
+            changes: [{ i: 'x', p: 0 }],
+            slice: 'x',
+            sliceStart: 0,
+            userIds: ['user-id-1'],
+          },
+        ]
+        this.DocumentManager.promises.acceptChangesWithLock.resolves({
+          changeContributors: this.changeContributors,
+          previews: this.previews,
+        })
         await this.HttpController.acceptChanges(this.req, this.res, this.next)
       })
 
@@ -706,10 +717,11 @@ describe('HttpController', function () {
         )
       })
 
-      it('should return a successful 200 with a list of the change contributors', function () {
+      it('should return a successful 200 with the contributors and previews', function () {
         this.res.status.should.have.been.calledWith(200)
         this.res.json.should.have.been.calledWith({
           changeContributors: this.changeContributors,
+          previews: this.previews,
         })
       })
 
@@ -736,6 +748,10 @@ describe('HttpController', function () {
           'ddddddddddddddddddddddd4',
         ]
         this.req.body = { change_ids: this.change_ids }
+        this.DocumentManager.promises.acceptChangesWithLock.resolves({
+          changeContributors: [],
+          previews: [],
+        })
         await this.HttpController.acceptChanges(this.req, this.res, this.next)
       })