## ADDED Requirements

### Requirement: SDK integration guide
The system SHALL include a document (`docs/engineering/11-sdk-guide.md`) that explains how each of the four language SDKs is structured, how to use them, and how to contribute to or extend them.

#### Scenario: SDK architecture overview present
- **WHEN** a new engineer reads 11-sdk-guide.md
- **THEN** they SHALL understand that all four SDKs (Node.js, Python, Go, Java) implement the same API surface (14 endpoints, 4 service clients, 1 TokenManager, 1 error type) with identical semantics, and why consistency across SDKs is a non-negotiable standard

#### Scenario: Node.js SDK documented
- **WHEN** a new engineer reads the Node.js SDK section
- **THEN** they SHALL find: installation (`npm install @sentryagent/idp-sdk`), the AgentIdPClient constructor, all 4 service clients (agents, credentials, tokens, audit), TokenManager auto-refresh behaviour, AgentIdPError structure, and a complete working code example for the most common flow (register agent → generate credential → issue token)

#### Scenario: Python SDK documented
- **WHEN** a new engineer reads the Python SDK section
- **THEN** they SHALL find: installation (`pip install sentryagent-idp`), both sync (AgentIdPClient) and async (AsyncAgentIdPClient) variants, TokenManager and AsyncTokenManager auto-refresh, AgentIdPError, and a complete working example for sync and async usage

#### Scenario: Go SDK documented
- **WHEN** a new engineer reads the Go SDK section
- **THEN** they SHALL find: installation (`go get github.com/sentryagent/idp-sdk-go`), AgentIdPClient construction, goroutine-safe TokenManager, context.Context usage pattern, AgentIdPError with Code/HTTPStatus/Details, and a complete working example

#### Scenario: Java SDK documented
- **WHEN** a new engineer reads the Java SDK section
- **THEN** they SHALL find: Maven/Gradle dependency snippet, AgentIdPClient construction with builder pattern, sync methods and CompletableFuture async counterparts, thread-safe TokenManager, AgentIdPException, and a complete working example

#### Scenario: SDK contribution guide included
- **WHEN** a new engineer needs to add a new endpoint to all SDKs
- **THEN** the guide SHALL provide a step-by-step checklist for adding a new method to all four SDKs consistently: where to add the method, what the signature pattern is, how to write the corresponding test, and how to verify it compiles/passes in each language