## Summary
Adds browser coverage for the missing-media runtime paths introduced by
#12069 and #12111:
- OSS: annotated `[output]` media is resolved from job history.
- Cloud: compact `[output]` media is resolved from output assets.
- OSS and Cloud: dropped video uploads do not surface a missing-media
error while the upload is still in progress.
This PR is now rebased directly onto `main`; the parent fix PRs have
been squash-merged, so this branch only contains the E2E coverage
commit.
## Test Fixtures
- Adds workflow fixtures for OSS spaced output annotations and Cloud
compact output annotations.
- Adds a small plain MP4 fixture for video drag/drop upload coverage.
## Validation
- `pnpm exec oxfmt --check
browser_tests/tests/propertiesPanel/errorsTabMissingMediaRuntime.spec.ts
browser_tests/assets/missing/missing_media_cloud_output_annotation.json
browser_tests/assets/missing/missing_media_output_annotations.json`
- `pnpm typecheck:browser`
- `pnpm exec oxlint
browser_tests/tests/propertiesPanel/errorsTabMissingMediaRuntime.spec.ts
--type-aware`
- `git diff --check origin/main..HEAD`
Note: before the rebase, the Cloud project target for this spec passed
locally. Local OSS project execution against the currently running Cloud
dist did not reach the test body because `ComfyPage.waitForAppReady`
timed out in `beforeEach`.
┆Issue is synchronized with this [Notion
page](https://www.notion.so/PR-12126-test-cover-missing-media-runtime-sources-35d6d73d365081f0a981c02f33c0ff84)
by [Unito](https://www.unito.io)
