DSN ingestion silently ignores Vue SDK envelopes sent as text/plain

[micopiira]

Environment

• Spotlight 4.11.8, running in Docker on localhost:8969
• @sentry/vue 10.73.0
• Chrome 152, macOS
• Application running at http://localhost:8080
• Standard Sentry DSN transport, without spotlightBrowserIntegration

Steps to Reproduce

1. Start Spotlight on port 8969.

2. Configure @sentry/vue in a browser application:

   import { init, captureException } from '@sentry/vue';
   
   init({
       dsn: 'http://spotlight@localhost:8969/0'
   });
   
   captureException(new Error('Vue DSN ingestion test'));

3. Inspect the outgoing network request:

   POST /api/0/envelope/?sentry_version=7&sentry_key=spotlight&sentry_client=sentry.javascript.vue%2F10.73.0
   Origin: http://localhost:8080
   Content-Type: text/plain;charset=UTF-8

4. Open Spotlight’s Errors view.

Expected Result

The exception should appear in Spotlight. A valid Sentry envelope sent through the Vue SDK’s standard DSN transport should be recognized and parsed.

This allows testing the application’s normal Sentry configuration locally without adding Spotlight-specific integrations to application code.

Actual Result

The request returns HTTP 200, but the event does not appear.

I verified the following against the same /api/0/envelope/ endpoint, with an Origin header present:

sentry_client	Content-Type	HTTP status	Exception displayed
sentry.javascript.vue/10.73.0	text/plain;charset=UTF-8	200	No
sentry.javascript.browser/10.73.0	text/plain;charset=UTF-8	200	Yes
sentry.javascript.vue/10.73.0	application/x-sentry-envelope	200	Yes

Changing only the SDK identifier in the query string or only the content type makes ingestion work.

The apparent cause is this condition in the ingestion handler:

if (
    ctx.req.query("sentry_client")?.startsWith("sentry.javascript.browser") &&
    ctx.req.header("Origin")
) {
    contentType = SENTRY_CONTENT_TYPE;
}

The correction introduced in #471 excludes sentry.javascript.vue, despite Vue using the same browser transport.

This is separate from #1295: the test envelopes contain actual exceptions with exception.values, rather than message-only events.