fix: update Swift protobuf codegen to match SDK runtime

[martinmitrevski]

Problem

protoc-gen-swift is pinned to 1.22.0 (install.sh), but stream-video-swift links SwiftProtobuf 1.38.1. Every regeneration therefore emitted code that fails Swift 6 builds, and the iOS team hand-patched it afterwards — patches that were wiped by the next regen:

• static var allCases instead of static let → "static property is not concurrency-safe"
• _StorageClass with no Sendable handling → hand-patched in the iOS SDK's Swift 6 migration
• deprecated init(serializedData:) instead of init(serializedBytes:)

Separately, the Swift twirp template had drifted badly from what the iOS SDK maintains by hand on top of the generated signal.twirp.swift — so those edits also had to be re-applied every time.

Changes

versions.sh — new PROTO_SWIFT_VERSION=1.38.1, alongside the other pinned tool versions, with a note that it must track the SwiftProtobuf runtime the consuming SDKs link.

install.sh — use that variable instead of the hardcoded 1.22.0.

tools/protoc-gen-swift-twirp/generator/template.goswift — brought in line with the hand-maintained client: retry handling via HTTPConfig, Response: ProtoModelResponse with hasError checks, the X-Stream-Client header, serializedBytes, and 4-space indentation.

1.38.1 emits nonisolated struct ...: @unchecked Sendable on messages and static nonisolated(unsafe) let defaultInstance, so Swift 6 is satisfied at the struct level and the hand-patched _StorageClass: @unchecked Sendable is no longer needed.

Verification

Built protoc-gen-swift 1.38.1 and the updated twirp plugin locally, regenerated video/sfu, dropped the output into stream-video-swift, and built StreamVideo for iOS Simulator: BUILD SUCCEEDED, zero errors and zero warnings from generated code. Diffing the new signal.twirp.swift against the hand-maintained one shows no semantic differences — only sendMetrics (genuinely new in the proto) and update(userToken:) moving below the generated methods.

Follow-ups for the iOS SDK (not in this PR)

• SendMetricsResponse is an empty message with no error field, so it can't satisfy ErrorProviding like the other responses. It needs an explicit conformance in ProtoModel.swift before the regenerated code compiles.
• That ErrorProviding list is hand-maintained, so every new RPC breaks the iOS build until someone adds a line. Worth considering having the template generate these conformances.

Rollout

Both changed files are baked into the Docker image at build time (Dockerfile does COPY . /home/ + RUN ./install.sh, and the template is go:embeded). So this needs to land on main → docker-image.yml rebuilds ghcr.io/getstream/protobuf-generate:latest → Scripts/generateCode.sh on the SDK side picks it up. Anyone with an existing /opt/.protoc install must re-run install.sh to get the new plugins locally.

🤖 Generated with Claude Code