chore(openspec): archive engineering-docs and phase-2-production-ready changes

- engineering-docs → archive/2026-03-29-engineering-docs (63/63 tasks complete)
- phase-2-production-ready → archive/2026-03-29-phase-2-production-ready (89/89 tasks complete)
- openspec/specs/ synced with all Phase 1 + Phase 2 + engineering-docs capabilities (22 specs total)

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

openspec/specs/java-sdk/spec.md

@@ -0,0 +1,23 @@
+# Spec: Java SDK (`ai.sentryagent:idp-sdk`)
+
+**Status**: Pending CEO approval
+**Workstream**: 4 of 8
+
+## Scope
+- `sdk-java/` directory at project root
+- `AgentIdPClient` with sync and `CompletableFuture` async variants
+- `TokenManager` with thread-safe cache and 60s auto-refresh
+- Service clients: `AgentRegistryClient`, `CredentialClient`, `TokenClient`, `AuditClient`
+- `AgentIdPException` extending `RuntimeException` with `code`, `httpStatus`, `details`
+- `pom.xml`: groupId=`ai.sentryagent`, artifactId=`idp-sdk`, Java 17+
+- `sdk-java/README.md`
+
+## Acceptance Criteria
+- [ ] All 14 endpoints covered
+- [ ] Sync methods return typed POJOs; async methods return `CompletableFuture<T>`
+- [ ] `AgentIdPException` thrown (not raw IOException) on all failure paths
+- [ ] `TokenManager` is thread-safe (`synchronized` on cache)
+- [ ] Apache HttpClient 5 for HTTP transport
+- [ ] Jackson for JSON serialization
+- [ ] `mvn verify` passes with >80% coverage (JUnit 5)
+- [ ] README matches Node.js SDK structure