test(perps): add reusable visible-pipeline probe

[abretonc7s]

Description

Stack 3 of the Perps performance instrumentation, based on #34948. Adds the development-only state machine used by the cross-platform perps.performance recipe to distinguish demand, resident/cache visibility, fresh lifecycle takeover, account/context generations, and the next-frame visible boundary.

The probe emits only through DevLogger when __DEV__ and explicitly activated. It adds no production telemetry and is kept separate from the product and Sentry contracts.

Stack

• Product behavior: perf(perps): preload homepage markets and account data #34934
• App/Homepage anchors: perf(perps): add app-to-homepage timing cohorts #34947
• Loading-session milestones: perf(perps): measure loading and reuse terminal trends #34948
• This PR: reusable development probe core
• Next: Homepage probe adapter/plumbing

Validation

• Probe suite: 5/5 PASS
• Targeted ESLint, Prettier, diff check: PASS
• Diff: 729 lines

Recipe

One cross-platform recipe: perps.performance. Platform is selected only by --device; no Android/iOS recipe copies.

[github-actions]

CLA Signature Action: All authors have signed the CLA. You may need to manually re-run the blocking PR check if it doesn't pass in a few minutes.

[github-actions]

🔍 Smart E2E Test Selection

• Selected E2E tags: None (no tests recommended)
• Selected Performance tags: None (no tests recommended)
• Risk Level: low
• AI Confidence: 95%

click to see 🤖 AI reasoning details

E2E Test Selection:
The PR adds two new files:

1. homepagePerformanceProbe.ts - A new DEV-only (__DEV__ gated) performance instrumentation utility for the Perps homepage. All logging and tracking functions return early when !__DEV__, meaning zero production behavior change. This is purely a developer debugging/instrumentation tool.
2. homepagePerformanceProbe.test.ts - A new unit test file for the above utility.

Both files are purely additive with no modifications to existing code. Since all production-facing code paths are unchanged and the new utility is entirely gated behind __DEV__ checks, no E2E tests need to run. There is no risk of breaking existing E2E tests or user flows.

Performance Test Selection:
The new homepagePerformanceProbe.ts file is a DEV-only instrumentation utility that measures performance internally but does not change any production rendering, data loading, or user-facing behavior. All functions are gated by __DEV__ checks and return early in production builds. This means no actual performance characteristics of the app are changed, so no performance test tags need to run.

View GitHub Actions results

[abretonc7s]

Consolidated into #34953 to keep the dev-validation delivery in one PR. The reviewed probe-core commits and tests are preserved there.