## Why
Diagnostic reports can span several envelopes, and the previous 10-second shared
network budget could expire before slow uploads and their attachments completed.
## What changed
- Give each diagnostic report a single five-minute deadline shared by the event,
attachments, retries, and retry backoff.
- Stop reading or sending later attachments once the deadline or a Sentry rate
limit is reached.
- Limit the app server to three concurrent report uploads and return an
overloaded JSON-RPC error for additional requests until a slot is released.
## Testing
Add coverage for slow multi-envelope reports, deadline-aware retries, skipped
attachments, rate-limit handling, and concurrency-slot release after failures.
GitOrigin-RevId: bdacf6c9731df16d2763e204565986eb6d540233
## Why
Submitting a diagnostic report could appear successful without confirming that Sentry accepted the upload, leaving callers unable to detect transport or HTTP failures.
## What changed
- Send report envelopes through the route-aware HTTP client and await the response.
- Reject redirects, propagate transport and non-success HTTP responses, and include the full error chain in upload JSON-RPC errors.
- Add structured logs for upload attempts, successes, and failures without including report contents.
## Testing
Added coverage for successful uploads, rejected responses, blocked redirects, transport failures, and app-server JSON-RPC error reporting.
GitOrigin-RevId: 07b5cfccd7a65f35d51a720537d2cd8962ed6cdb
