Release v0.30.0-rc.0

[Magmusacy]

Bumps the SDK to 0.30.0-rc.0, matching the @fishjam-cloud/react-native-webrtc prerelease in fishjam-cloud/fishjam-react-native-webrtc#79.

Changes

• 0.29.0 -> 0.30.0-rc.0 in the root package and the seven published workspaces (webrtc-client, ts-client, react-client, react-native-client, react-native-custom-video-source, react-native-vision-camera-source, ios-expo-voip).

Cross-package deps are all workspace:*, so nothing else needs editing — Yarn resolves them at pack time. yarn.lock is unchanged (workspaces resolve to 0.0.0-use.local) and yarn install --immutable passes.

Proto output is intentionally not regenerated here: yarn gen:proto pulls a newer packages/protobufs/protos commit and rewrites the protoc version banner, which is unrelated to a version bump.

Order of operations

The mobile-client, ios-expo-voip, custom-video-source and vision-camera-source publish jobs run check:webrtc-published, which requires the packages/react-native-webrtc submodule to sit on a tag matching its own package.json version, with that version live on npm. So:

1. Merge Bump version to 0.30.0-rc.0 fishjam-react-native-webrtc#79 and publish @fishjam-cloud/react-native-webrtc@0.30.0-rc.0 (prerelease, lands under the rc dist-tag).
2. Merge this PR.
3. Pin the submodule to v0.30.0-rc.0 on main (separate commit, as in Pin react-native-webrtc submodule to v0.29.0 tag #570).
4. gh release create v0.30.0-rc.0 --target main --generate-notes --prerelease — publishing the release triggers .github/workflows/release.yaml, and --prerelease makes it publish under the rc npm tag so latest stays at 0.29.0.