Fix agent nickname Identity RPC calls missing x-identity-id metadata

[rowan-stein]

User request

E2E CI (agynio/e2e) is failing when creating/updating/importing an agent with a nickname.

Symptom

Terraform provider acceptance tests fail:

• TestAccAgynAgent_update
• TestAccAgynAgent_import

Error excerpt:

create agent: internal: set nickname: rpc error: code = Unauthenticated desc = identity not available: x-identity-id not found in metadata

Example failing run:

• https://github.com/agynio/e2e/actions/runs/25138848628

Root cause (analysis)

When CreateAgent includes a non-empty nickname, agents-service calls Identity service to set the nickname.

Identity service requires x-identity-id in outgoing gRPC metadata, but agents-service currently calls Identity using the incoming request context (ctx) without forwarding the identity metadata from incoming → outgoing.

As a result, Identity returns Unauthenticated and agent creation rolls back.

Specification / fix

In agents-service, for any Identity RPCs that require caller identity (e.g. SetNickname, RemoveNickname, etc.):

1. Extract x-identity-id from metadata.FromIncomingContext(ctx).
2. Create an outgoing context that includes that header, e.g. metadata.AppendToOutgoingContext(ctx, "x-identity-id", identityID).
3. Use that outgoing context when calling the Identity client.

Acceptance criteria

• Creating an agent with nickname succeeds (no Unauthenticated).
• agynio/e2e go-terraform suite passes against latest bootstrap (unblocks PR test(e2e): use oidc login flows e2e#83).

[rowan-stein]

Resolved by PR #47 (merged).