Release activity email links to single-project view, hiding commits visible in other projects

## Environment

- Sentry SaaS (codecov.sentry.io)

## Description

When a release spans multiple projects, the release activity email notification references commits from across all projects but links to a single project's view of the release. This causes confusion when the linked project shows fewer commits than what the email claims are included.

## Steps to Reproduce

1. Have a release that is associated with multiple projects (e.g., `production-release-18dc1f3` associated with `worker`, `api`, and `ecdn-api` projects)
2. Each project may have different commit associations due to how/when the release was created for each project
3. Receive a release activity email saying "your commits were deployed"
4. Click the link in the email, which goes to a URL like:
`https://codecov.sentry.io/releases/production-release-18dc1f3/?project=5215654`

## Expected Behavior

Either:
- The email link should go to a cross-project release view that shows all commits across all projects with that release ID
- Or the email should only reference commits that are visible in the specific project being linked

## Actual Behavior

- The email says my commits are part of the release
- The link goes to a single project's view of the release
- That project's view only shows 1 commit (not mine)
- My commits are associated with the release in a different project, but there's no way to see that from the linked page

## Example

- Release: `production-release-18dc1f3`
- Projects in release: `ecdn-api`, `worker`, `api`
- Email link project: `5215654`
- Email claims my commits are included
- Linked page shows only 1 commit by a different author

## Additional Context

This appears to happen when a release is created separately for each project (e.g., via `getsentry/action-release` in separate CI jobs), and each project ends up with different commit associations. The email aggregates across all projects, but the link is project-specific.

No source file or test is named. Start by tracing release activity email generation and how the project parameter is added to the release URL, then compare the email's cross-project commit aggregation with the linked project's release view. Done means the email link and displayed commits consistently represent the release across its associated projects.

Written by the indexing model from the issue text.