fix(ui): adjusts alignment of elements to prevent incomplete scroll

[ldelelis]

What does this PR do?

Fixes an UI issue where, on sessions with enough messages, the sidebar on <ENTERPRISE_URL>/share/<SESSION_ID>'s desktop viewport would fail to display the first few messages.

Fixes #11650

How did you verify your code works?

1. Setup local opencode and enterprise
2. Import or generate a session with enough messages (40+ in my case)
3. Share the session with /share
4. Open in browser and check the sidebar's scroll results

Demo video, comparing before/after side by side

demofix.mp4

[github-actions]

Hey! Your PR title adjusts alignment of elements to prevent incomplete scroll doesn't follow conventional commit format.

Please update it to start with one of:

• feat: or feat(scope): new feature
• fix: or fix(scope): bug fix
• docs: or docs(scope): documentation changes
• chore: or chore(scope): maintenance tasks
• refactor: or refactor(scope): code refactoring
• test: or test(scope): adding or updating tests

Where scope is the package name (e.g., app, desktop, opencode).

See CONTRIBUTING.md for details.

[github-actions]

The following comment was made by an LLM, it may be inaccurate:

No duplicate PRs found

[github-actions]

Thanks for your contribution!

This PR doesn't have a linked issue. All PRs must reference an existing issue.

Please:

1. Open an issue describing the bug/feature (if one doesn't exist)
2. Add Fixes #<number> or Closes #<number> to this PR description

See CONTRIBUTING.md for details.