Rename root, api and sdk module paths (imports, go.mod, go_package,
ldflags, build scripts, buf configs) and regenerate protobuf/gateway
code with the project's pinned toolchain. Wire identifiers unchanged.
api gets a local replace for sdk; root/api/sdk require v0.1.0.
Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>
* fix (events): convert multierror to stdlib error
multierror errors will be converted to a stdlib error (because
multierror doesn't support json marshaling).
* refact (errors): convert from multierror to stdlib errors.Join(...)
* refact: convert from pkg/errors to stdlib error wrapping