[proto] add canonical organization membership type

[haasonsaas]

Summary

• add identity.v1.OrganizationMembership as the canonical org-plus-role view
• keep Organization entity-scoped and avoid pushing membership context onto it
• regenerate Go and TypeScript outputs

Why

Chat's ListWorkspaces needs a shared type for "organization plus this user's role in it". That is a membership-scoped view, not an intrinsic property of Organization.

Validation

• make lint generate
• go build ./...

Follow-up

• consumed by evalops/chat#885

[cursor]

PR Summary

Low Risk
Low risk schema addition: introduces a new protobuf message and regenerates Go/TS code, with no behavioral logic changes. Main risk is downstream compile/runtime incompatibilities for consumers that assume previous generated message indices/types.

Overview
Adds a new protobuf message OrganizationMembership to represent an Organization plus the current user’s role, keeping membership-scoped fields off Organization.

Regenerates Go and TypeScript outputs to include the new type and shifts generated message indices/descriptor metadata for existing Member and APIKey types accordingly.

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