Clickable user profile view from issue/event detail page

### Problem Statement

When `setUser()` / user context is configured via the SDK, user metadata (`id`, `username`, `email`, `ip_address`) is displayed in the issue/event detail sidebar — but as static, non-interactive text. The data is clearly indexed, since Discover and issue search support queries like `user.email:jane@example.com`, `user.id:123`, and `has:user`. However, there is no way to click on a user in the issue UI and navigate to a view of everything associated with that user.

To answer "what else has this user experienced?" you must either:
1. Manually construct a Discover query using `user.email:` / `user.id:` syntax
2. Create and maintain saved searches for this pattern
3. Know the search syntax exists in the first place

The underlying data is already captured, indexed, and queryable — it's the access path from the UI that's missing.

### Solution Brainstorm

- Make user identifiers (`email`, `username`, `id`, `ip_address`) in the issue/event detail sidebar clickable
- Link to a dedicated User Profile page (or pre-filtered Discover query) scoped to that user identity, showing:
- All issues/errors associated with the user across the project (or org)
- Event timeline
- Session Replay links (if available)
- User Feedback entries (if any)
- The existing "Users Affected" count on issues could also benefit — clicking a user in that list could navigate to the same view
- This would make the already-supported `user.email:X` / `user.id:X` query semantics accessible without requiring users to know Sentry's search syntax

Start by reviewing the issue/event detail sidebar and the existing Discover query behavior for user.email, user.id, and has:user. Done should include a decided navigation target and clickable user identifiers that expose the associated issues, timeline, and any available replay or feedback entries.

Written by the indexing model from the issue text.