refactor: unify tarball resolution and optimize download latency

[aprendendofelipe]

• Replace multiple specific endpoints with a global tarball-resolver middleware.
• Remove 302 redirects.
• Eliminate routing hacks required to prevent Nitro from hijacking Vue's / and /~/... routes.
• Improve E2E testability by introducing x-commit-key and x-pkg-name-key headers.
• Make analytics database writes non-blocking (event.waitUntil).

[aprendendofelipe]

Marking as draft. I need to fix a bug when ref is a branch name containing @. I'll check this out later.

[aprendendofelipe]

I updated the workflow_run.in_progress.json fixture to use a chaotic branch name (@test/@chaotic.branch/name-@v1.@) to stress-test the resolver. Interestingly, I noticed the current version of the service also fails to parse this payload correctly. This PR fixes that pre-existing bug!