[yfang-figma]

Written with AI

Let the official SDK own Temporal protobuf messages when COINBASE_TEMPORAL_RUBY_DISABLE_PROTO_LOAD=1. Keep the Coinbase gRPC stubs and preserve default Coinbase-only loading. Apply the same guard after proto regeneration. This is a narrow adaptation of Coinbase PR 335, not an application-level require hook.

The option must be set before the first Coinbase require, after the official API classes load. It does not permit different Workflow runtimes to poll the same Task Queue. The official gem is a test dependency only.

Test plan

• BUNDLE_GEMFILE=gemfiles/temporalio.gemfile bundle exec rspec spec/unit/lib/temporal/protobuf_loading_spec.rb: 2 examples pass. The dual-SDK regression fails on the original library files with duplicate protobuf descriptors.
• The new probes plus existing gRPC and serializer specs pass: 74 examples, 0 failures, on Ruby 3.4.7 and temporalio 1.10.1.
• Full unit suite with --require ostruct: 647 examples, 7 failures. The same 7 replay/backtrace failures reproduce with the original library files on Ruby 3.4. No unrelated fixes are included.
• Proto regeneration was not run because the API submodule is absent in this checkout. make -n proto and git diff --check pass.

Application preload, fork, worker polling, and devenv01 validation belong to the dependent Figma investigation PRs.