fix: make date chip gliding work with new virtualized list system

[pranithakshayreddy-tech]

### Proposed changes
The floating date chip "gliding" effect was broken after the migration to the new virtualized list system.
The old code used a CSS selector targeting data-time='YYYYMMDD' to hide the date divider behind the floating chip. However, the new system uses data-id with a Unix timestamp instead.
Updated the listStyle CSS selector in useDateScroll.ts to target data-id using new Date(bubbleDate.date).getTime() to match the correct divider element and restore the gliding behavior.
### Issue(s)
Related to the TODO comment at useDateScroll.ts#L148
### Steps to test or reproduce

Open any room with many messages
Scroll up quickly through the message list
Observe the floating date chip at the top
The date divider behind the chip should now be hidden (opacity: 0)
Previously the divider was visible behind the chip — now it is correctly hidden

### Further comments
The removed TODO comment confirms this was a known issue left for future fixing after the virtualized list migration. No new dependencies or breaking changes introduced.

Summary by CodeRabbit

• Bug Fixes
  • Enhanced the display of date dividers when scrolling through message history in rooms.

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📒 Files selected for processing (1)

• apps/meteor/client/views/room/hooks/useDateScroll.ts

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Files:

• apps/meteor/client/views/room/hooks/useDateScroll.ts

🧠 Learnings (5)

📚 Learning: 2026-02-10T16:32:42.586Z

Learnt from: tassoevan
Repo: RocketChat/Rocket.Chat PR: 38528
File: apps/meteor/client/startup/roles.ts:14-14
Timestamp: 2026-02-10T16:32:42.586Z
Learning: In Rocket.Chat's Meteor client code, DDP streams use EJSON and Date fields arrive as Date objects; do not manually construct new Date() in stream handlers (for example, in sdk.stream()). Only REST API responses return plain JSON where dates are strings, so implement explicit conversion there if needed. Apply this guidance to all TypeScript files under apps/meteor/client to ensure consistent date handling in DDP streams and REST responses.

Applied to files:

• apps/meteor/client/views/room/hooks/useDateScroll.ts

📚 Learning: 2026-05-11T20:30:35.265Z

Learnt from: tassoevan
Repo: RocketChat/Rocket.Chat PR: 40480
File: apps/meteor/client/meteor/startup/accounts.ts:59-61
Timestamp: 2026-05-11T20:30:35.265Z
Learning: In Rocket.Chat’s Meteor client code, when calling `dispatchToastMessage` with `{ type: 'error' }`, pass the raw caught error object as `message` without manual normalization. `dispatchToastMessage` is designed to accept `message: unknown` for error toasts, so avoid converting errors to strings (e.g., `String(error)`) or extracting `error.message` before passing them.

Applied to files:

• apps/meteor/client/views/room/hooks/useDateScroll.ts

📚 Learning: 2026-02-26T19:25:44.063Z

Learnt from: gabriellsh
Repo: RocketChat/Rocket.Chat PR: 38778
File: packages/ui-voip/src/providers/useMediaSession.ts:192-192
Timestamp: 2026-02-26T19:25:44.063Z
Learning: In the Rocket.Chat repository, do not reference Biome lint rules in code review feedback. Biome is not used even if biome.json exists; only reference Biome rules if there is explicit, project-wide usage documented. For TypeScript files, review lint implications without Biome guidance unless the project enables Biome rules.

Applied to files:

• apps/meteor/client/views/room/hooks/useDateScroll.ts

📚 Learning: 2026-02-26T19:25:44.063Z

Learnt from: gabriellsh
Repo: RocketChat/Rocket.Chat PR: 38778
File: packages/ui-voip/src/providers/useMediaSession.ts:192-192
Timestamp: 2026-02-26T19:25:44.063Z
Learning: In this repository (RocketChat/Rocket.Chat), Biome lint rules are not used even if a biome.json exists. When reviewing TypeScript files (e.g., packages/ui-voip/src/providers/useMediaSession.ts), ensure lint suggestions do not reference Biome-specific rules. Rely on general ESLint/TypeScript lint rules and project conventions instead.

Applied to files:

• apps/meteor/client/views/room/hooks/useDateScroll.ts

📚 Learning: 2026-05-06T12:21:44.083Z

Learnt from: juliajforesti
Repo: RocketChat/Rocket.Chat PR: 40256
File: apps/meteor/client/components/CreateDiscussion/CreateDiscussion.tsx:121-149
Timestamp: 2026-05-06T12:21:44.083Z
Learning: Field wrappers in rocket.chat/fuselage-forms (Field, FieldLabel, FieldRow, FieldError, FieldHint) auto-create htmlFor/id associations, aria-describedby, and role="alert" for errors. Do not manually set htmlFor, id, aria-describedby, or role attributes when using these wrappers. This automatic wiring does not apply to plain rocket.chat/fuselage components, which require explicit ID wiring per the accessibility docs. In code reviews, prefer using fuselage-forms wrappers for form fields and verify there is no unnecessary manual ID/aria wiring in files that use these wrappers. If a component uses plain fuselage components, ensure proper id wiring as per docs.

Applied to files:

• apps/meteor/client/views/room/hooks/useDateScroll.ts

🔇 Additional comments (1)

apps/meteor/client/views/room/hooks/useDateScroll.ts (1)

148-156: LGTM!

---

Walkthrough

The PR updates the useDateScroll hook to dynamically compute a listStyle CSS block that hides the date divider matching the current bubbleDate via data-id attribute targeting. The previous hardcoded undefined value and older commented selector logic are replaced with conditional CSS generation.

Changes

Date Divider Visibility

Layer / File(s)	Summary
ListStyle CSS computation apps/meteor/client/views/room/hooks/useDateScroll.ts	useDateScroll now derives listStyle from bubbleDate.show and bubbleDate.date to conditionally apply CSS hiding the current date divider via [data-id='<timestamp>'] selector with opacity: 0, replacing the previous hardcoded undefined assignment.

Estimated code review effort

🎯 2 (Simple) | ⏱️ ~10 minutes

Possibly related issues

• Make the chip "gliding" work with the new sistem. #40620: The main change replaces the previous data-time/string-processed selector with a new data-id-based listStyle to hide the current date divider.

Suggested labels

type: bug

🚥 Pre-merge checks | ✅ 5

✅ Passed checks (5 passed)

Check name	Status	Explanation
Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.
Title check	✅ Passed	The title clearly and specifically describes the main fix: restoring the date chip gliding effect after migration to a virtualized list system, which aligns perfectly with the changeset.
Docstring Coverage	✅ Passed	No functions found in the changed files to evaluate docstring coverage. Skipping docstring coverage check.
Linked Issues check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Out of Scope Changes check	✅ Passed	Check skipped because no linked issues were found for this pull request.

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