Accept invitation flow consumes invite with the currently logged-in account instead of the invited email

### Environment

SaaS (https://sentry.io/)

### Steps to Reproduce

1. Log into Sentry with Account A (email A) in the browser.
2. From a different account, send an organization invitation to email B.
3. Open email B's inbox (while still logged in as A in the same browser) and click the "Accept" / "Join" link in the invitation email.
4. Observe which account is added to the organization.

### Expected Result

The invitation should be bound to email B. Sentry should either:
- Accept the invite as email B, or
- Detect the mismatch between the logged-in account (A) and the invited email (B), and prompt the user to sign out and sign in as B before joining.

In no case should an invite sent to email B be silently consumed by a different account.

### Actual Result

The invitation was accepted by Account A. Email A was added to the organization that was only ever invited to email B. There was no warning, no confirmation step, and no indication that the logged-in account did not match the invited email.

This effectively lets the wrong identity end up inside the wrong organization without the user realizing it, which is a significant identity/access issue for an invitation flow.

### Product Area

Sign In

### Link

_No response_

### DSN

_No response_

### Version

_No response_

The report names no files, tests, or code entry points. Start by locating the invitation acceptance flow and its identity checks, then reproduce the mismatch between the logged-in account and invited email. Done means an invitation cannot be silently consumed by a different account and instead accepts the invited identity or prompts for the correct sign-in.

Written by the indexing model from the issue text.