Add evidence audit open PR hygiene

[RicheyWorks]

Summary

Slot 2 of the LoadBalancerPro 20-PR Evidence Audit and Closeout Repair Campaign.

This PR adds a docs/test-only open PR hygiene audit. It documents the current open PR inventory, records PR #291 as open but DIRTY / CONFLICTING and likely stale or superseded by current main, and explicitly says not to close, rebase, edit, merge, or otherwise modify unrelated PRs without human direction.

It also advances the campaign board/session checkpoint after slot 1 merged and main CI/CodeQL were green, and adds a read-only documentation guard for the slot 2 audit artifact.

Verification

• mvn test "-Dtest=AgentEvidenceAuditOpenPrHygieneDocumentationTest" passed after one logged wording repair.
• mvn test "-Dtest=AgentEvidenceAuditOpenPrHygieneDocumentationTest,AgentEvidenceAuditCampaignCloseoutRepairDocumentationTest,AgentGoalCampaignFinalHandoffReportDocumentationTest,AgentGoalCampaignBoardInitializationDocumentationTest,AgentGoalCampaignTemplateArchitectureDocumentationTest,AgentGoalModeLongRunProtocolDocumentationTest,AgentWorkflowQuickstartDocumentationTest,AdvancedReadmeAgentContractDocumentationTest" passed after one logged guard durability repair.
• mvn -B dependency:tree "-Dincludes=org.apache.tomcat.embed" passed.
• mvn -q test passed with 2,392 tests.
• mvn -q "-DskipTests" package passed.
• mvn -B package passed with 2,392 tests.
• git diff --check passed with line-ending warnings only.
• git diff --check origin/main...HEAD passed.
• git diff --cached --check passed.
• .\scripts\smoke\enterprise-lab-workflow.ps1 -Package passed.

Failures Logged

• Focused guard missed exact documentation/test-only wording; fixed and logged in docs/agent/FAILURE_LOG.md.
• Prior slot guard froze the active board to slot 1; made durable and logged.
• Slot 2 checkpoint phrase drifted after local verification update; fixed and logged.

Scope / Safety Audit

• Docs/test-only.
• No production code changes.
• No Maven config changes.
• No CI/workflow changes.
• No Dockerfile or Compose changes.
• No runtime behavior or endpoint changes.
• No k6, Bruno, Toxiproxy, script, runner service, automation, secret, external/cloud/tenant target, or production-looking default changes.
• Does not claim production readiness, production certification, live-cloud validation, real-tenant validation, runtime enforcement, load/stress/benchmarking, throughput/p95/p99 evidence, replay/evidence/report/storage/export proof, or broader automation.