feat: add visual warning for mismatched commit email

[voiduin]

Description

When the commit email doesn't match the linked account, the existing warning is easy to miss - it's just a small yellow triangle on the avatar. First-time users especially have no idea what it means or what to do about it.

This PR makes the misattribution warning more noticeable and actionable:

1. More visible:

• Added a yellow accent line on the left side of the commit author area
• The email text turns yellow to draw attention

2. More helpful tooltip:

• Shows a clear message: "Email does not match linked account"
• Hints which account the repository is currently linked to
• Provides a direct link to repository settings where the user can fix it

The goal is simple - when this mismatch happens, users should notice it faster and understand what to do without guessing.

Screenshots

1. Before changes

Only a small triangle icon on the avatar, no explanation of what's wrong or how to fix it

2. After changes

(1) yellow accent line
(2) colored email make the warning visible at a glance
(3) and the tooltip explains the problem with a link to fix it
(4) Action text and direct link to place in settings

How to reproduce:

• Sign in with your GitHub account
• Open a repository linked to that account
• Set a different email in git config (e.g. git config user.email "other@example.com")
• Go to the Changes tab - the warning should appear in the commit author area
• Hover over the email to see the tooltip with details

Release notes

Notes: When commit email doesn't match the linked repository account, the warning is now more visible with a yellow accent line and colored email text. The tooltip explains the issue and links directly to repository settings.

[pol-rivero]

Looks good to me, thanks!