ci(perf): add trusted paired JMH A/B gate (#55)

Add a base-owned, label-gated paired JMH A/B workflow with A/A noise validation, protected benchmark surfaces, isolated evidence collection, statistical guardrails, and standard Paper live-evidence tooling.

Author: TypeThe0ry

.github/workflows/ensure-labels.yml

@@ -21,7 +21,11 @@ jobs:
             const labels = [
               { name: "dependencies", color: "0366d6", description: "Dependency updates" },
               { name: "gradle", color: "0e8a16", description: "Gradle build and dependency updates" },
-              { name: "github-actions", color: "5319e7", description: "GitHub Actions workflow updates" }
+              { name: "github-actions", color: "5319e7", description: "GitHub Actions workflow updates" },
+              { name: "performance-ab", color: "d4c5f9", description: "Run the base-owned paired performance gate" },
+              { name: "performance-snapshot", color: "bfdadc", description: "Use the viewer snapshot performance profile" },
+              { name: "performance-gb-bot", color: "bfdadc", description: "Use the GB bot decision performance profile" },
+              { name: "performance-ray-proxy", color: "bfdadc", description: "Use the client ray-proxy performance profile" }
             ];
 
             for (const label of labels) {