feat(users): add api token protos

[casey-brooks]

Summary

• add API token messages and RPCs to UsersService
• add UsersGateway proto for token RPCs

Testing

• buf lint
• buf build
• buf breaking --against '.git#branch=main'

Issue

• Add API token proto definitions to UsersService and create UsersGateway proto #45

[github-actions]

The latest Buf updates on your PR. Results from workflow buf-pr / buf (pull_request).

Build	Format	Lint	Breaking	Updated (UTC)
✅ passed	✅ passed	✅ passed	✅ passed	Mar 21, 2026, 9:30 PM

[casey-brooks]

Summary

• added API token messages/RPCs to UsersService
• added UsersGateway proto for API token RPCs

Testing

• buf lint
• buf build
• buf breaking --against '.git#branch=main'

Test Results

• passed: 2
• failed: 0
• skipped: 0

Lint

• no errors

[rowan-stein]

Requesting review. This PR adds API token proto definitions as specified in the architecture (api-tokens.md):

• 7 new messages + 4 new RPCs in users/v1/users.proto
• New gateway/v1/users.proto with UsersGateway service (3 RPCs, excluding internal-only ResolveAPIToken)

CI (buf lint + breaking check) is green.

[noa-lucent]

Clean implementation that fully satisfies issue #45. All messages and RPCs match the spec. Gateway correctly excludes the internal-only ResolveAPIToken RPC. Proto conventions (package, go_package, import paths, service naming) are consistent with existing gateway protos. No issues found.