Load sanity for the session endpoint on Neon

[pataniaeli]

Ticket: AUTH-T98 · Epic: E13 Testing & QA · Phase: Phase 3 — Hardening, observability, Chambers
Priority: Low · Estimate: 2 points · Labels: epic:testing, phase:3, testing, performance

Depends on:

• Session endpoint for products: user, email, positions, admin flags #40 — AUTH-T28 Session endpoint for products: user, email, positions, admin flags
• Create the Vercel project, custom domains, environments, and Neon preview branching #16 — AUTH-T05 Create the Vercel project, custom domains, environments, and Neon preview branching

Run a k6/autocannon script against the dev deployment: 100 concurrent virtual users hitting /api/sgauth/session with valid cookies for 2 minutes. Record p50/p95, Neon connection count, and any pooler saturation; tune pool size and Neon compute settings; document results.

Acceptance criteria

• p95 < 250 ms and zero connection errors at 100 VUs; results in docs/PERFORMANCE.md.

_{Generated from the SGAuth design (docs/sgauth-design in SGAOperations/auth). SGAuth is built on Neon and does not use Supabase.}